.NET on Junian Dev

Install .NET 11 SDK Preview on macOS Side-by-Side with Homebrew

author@junian.dev (Junian Triajianto) — Mon, 23 Feb 2026 04:00:00 +0700

Microsoft recently released .NET 11 Preview 1.

If you want to try it without removing your existing installed .NET SDKs on macOS, you can install it side-by-side using the Homebrew package manager.

First, tap the Homebrew repository I maintain:

brew tap junian/homebrew-dotnet

Then install the .NET 11 SDK Preview:

How to Install Visual Studio Community 2017 and Fix the Startup Error

author@junian.dev (Junian Triajianto) — Thu, 12 Feb 2026 19:00:00 +0700

Ah Yes. Visual Studio 2017. What a good memory. That was a good year before COVID-19 happened.

I still install it sometimes, especially when dealing with older projects that don’t behave nicely in newer Visual Studio versions. Legacy apps are real, and sometimes the safest move is just using the original toolchain.

Here’s how I install Visual Studio 2017 Community Edition plus how I fix that annoying System.InvalidOperationException startup error that sometimes appears right after installation.

Fixing .NET SDK Resolver Failure

author@junian.dev (Junian Triajianto) — Wed, 11 Feb 2026 15:00:00 +0700

Recently, with .NET 10.0.103 installed on my macOS (it also happened on Windows and probably Linux too), I tried to run a C# script and ran into this issue.

$ dotnet run Program.cs
SDK Resolver Failure: "The SDK resolver "Microsoft.DotNet.MSBuildWorkloadSdkResolver" failed while attempting to resolve the SDK "Microsoft.NET.SDK.WorkloadAutoImportPropsLocator". Exception: "System.IO.FileNotFoundException: Workload manifest microsoft.net.workload.emscripten.current: 10.0.102/10.0.100 from workload version 10.0.102 was not installed. Running "dotnet workload repair" may resolve this.
   at Microsoft.NET.Sdk.WorkloadManifestReader.SdkDirectoryWorkloadManifestProvider.GetManifests()
   at Microsoft.NET.Sdk.WorkloadManifestReader.WorkloadResolver.LoadManifestsFromProvider(IWorkloadManifestProvider manifestProvider)
   at Microsoft.NET.Sdk.WorkloadManifestReader.WorkloadResolver.InitializeManifests()
   at Microsoft.NET.Sdk.WorkloadManifestReader.WorkloadResolver.GetInstalledWorkloadPacksOfKind(WorkloadPackKind kind)+MoveNext()
   at Microsoft.NET.Sdk.WorkloadMSBuildSdkResolver.CachingWorkloadResolver.Resolve(String sdkReferenceName, IWorkloadManifestProvider manifestProvider, IWorkloadResolver workloadResolver)
   at Microsoft.NET.Sdk.WorkloadMSBuildSdkResolver.CachingWorkloadResolver.Resolve(String sdkReferenceName, String dotnetRootPath, String sdkVersion, String userProfileDir, String globalJsonPath)
   at Microsoft.NET.Sdk.WorkloadMSBuildSdkResolver.WorkloadSdkResolver.Resolve(SdkReference sdkReference, SdkResolverContext resolverContext, SdkResultFactory factory)
   at Microsoft.Build.BackEnd.SdkResolution.SdkResolverService.TryResolveSdkUsingSpecifiedResolvers(IReadOnlyList`1 resolvers, Int32 submissionId, SdkReference sdk, LoggingContext loggingContext, ElementLocation sdkReferenceLocation, String solutionPath, String projectPath, Boolean interactive, Boolean isRunningInVisualStudio, SdkResult& sdkResult, IEnumerable`1& errors, IEnumerable`1& warnings)""  /usr/local/share/dotnet/sdk/10.0.103/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.ImportWorkloads.props

The build failed. Fix the build errors and run again.

.NET SDK Resolver Failure

As suggested by the error message, I tried dotnet workload repair hoping it would fix the issue, but another error message appeared:

Installing Visual Studio 2019 Community Edition (Step by Step)

author@junian.dev (Junian Triajianto) — Sun, 08 Feb 2026 19:00:00 +0700

Visual Studio 2019 might not be the newest kid on the block anymore, but it’s still very useful—especially if you’re working on legacy projects or older .NET Framework applications.

I still install it from time to time, usually when dealing with an older codebase or opening an open-source repository that works best with VS 2019. So here’s a quick, no-nonsense walkthrough of how I install Visual Studio 2019 Community Edition.

Visual Studio Older Downloads (ISO + Installer): 2022, 2019, 2017, 2015, 2013

author@junian.dev (Junian Triajianto) — Tue, 03 Feb 2026 19:00:00 +0700

Some people have asked me to list all official Microsoft Visual Studio download links from 2013 through 2026 for the Community, Professional, and Enterprise editions.

As you may know, Microsoft often hides older Visual Studio download links whenever a new version is released.

So, instead of letting my fellow developers go down the Microsoft website rabbit hole, I decided to collect and index the download links here.

Is It Safe and Genuine?

Good question. Never trust anything on the internet, including my website.

How to Deploy a Blazor WebAssembly Standalone App to GitHub Pages

author@junian.dev (Junian Triajianto) — Fri, 30 Jan 2026 19:00:00 +0700

If you have ever built a .NET Blazor WebAssembly app, you may have separated the frontend and backend. Since Blazor WASM is essentially just the frontend, you can deploy it to most static site hosting services, including GitHub Pages.

Let’s get straight to the point. Follow these steps to create, publish, and deploy your standalone Blazor WebAssembly app.

Install the latest .NET SDK.

Create a new Blazor WebAssembly standalone app project. Let’s name it BlazorApp.

Deploy a .NET 10 Blazor WebAssembly App to Cloudflare Pages

author@junian.dev (Junian Triajianto) — Wed, 28 Jan 2026 07:06:56 +0700

Blazor is a modern way to build web applications. Instead of relying on JavaScript, it allows you to use C#. That’s the dream! In this guide, you’ll learn how to create a web application using Blazor and deploy it online using Cloudflare Pages.

Enough introduction. Let’s get started!

Install .NET 10

Blazor works with C#. To start a Blazor project, you need to install the .NET SDK. Simply download it and follow the installation instructions from the official website.

Blazor Apps by Junian.dev

author@junian.dev (Junian Triajianto) — Wed, 28 Jan 2026 06:00:00 +0700

Installing Multiple .NET Versions on macOS with Homebrew

author@junian.dev (Junian Triajianto) — Wed, 03 Dec 2025 09:25:59 +0700

If you’re a .NET developer using macOS, you may want to install multiple .NET SDK versions side by side. While you can do this manually, it can become a headache to maintain in the long term. As you install more SDKs, leftover files can accumulate and fill up your storage.

Uninstalling older versions manually can also be tedious. You can refer to the official documentation for removal instructions. I even wrote an uninstallation guide to remind myself how to do it properly.

Visual Studio Professional Downloads - 2026, 2022, 2019, 2017, 2015

author@junian.dev (Junian Triajianto) — Fri, 21 Nov 2025 10:00:00 +0700

When working with older .NET Framework projects, you may encounter issues when using the latest version of Visual Studio.

Fortunately, this can be easily resolved by installing an older version of Visual Studio.

If you’re a small business or part of a team, you likely already have a Visual Studio Professional license. That may lead you to wonder: where can you download older versions of Visual Studio Professional?

If you’re a solo developer, open-source contributor, or hobbyist, you can use the Visual Studio Community edition for free. If you’re working in an enterprise environment, you’ll need the Visual Studio Enterprise edition.

Visual Studio Enterprise Downloads - 2026, 2022, 2019, 2017, 2015

author@junian.dev (Junian Triajianto) — Fri, 21 Nov 2025 09:00:00 +0700

It’s sometimes frustrating to open old or legacy .NET Framework projects with the latest version of Visual Studio.

Fortunately, this can be easily solved by installing an older version of Visual Studio.

Due to company policy or other requirements, you may need the Visual Studio Enterprise edition. That often leads to the question: where can you download older versions of Visual Studio Enterprise?

If you’re a small business, you may want to get the Visual Studio Professional edition. If you’re a solo developer, open-source contributor, or hobbyist, you can use the Visual Studio Community edition for free.

Visual Studio Community Downloads - 2026, 2022, 2019, 2017, 2015, 2013

author@junian.dev (Junian Triajianto) — Wed, 12 Nov 2025 04:37:55 +0700

It’s sometimes frustrating to open old or legacy .NET Framework projects with the latest version of Visual Studio.

Fortunately, this can be easily solved by installing an older version of Visual Studio.

If you’re a small business, you may want to get the Visual Studio Professional edition. If you’re working in an enterprise environment, you’ll need the Visual Studio Enterprise edition.

While older Professional or Enterprise versions of Visual Studio are usually available on Microsoft’s website, the Community edition is not as easy to find.

Run a .NET App from a Single C# File

author@junian.dev (Junian Triajianto) — Sat, 27 Sep 2025 05:44:27 +0700

With .NET 10, you can run a C# file directly, no project or solution file required!

This is especially useful for automation scripts, DevOps tasks, or quick experimentation.

In this tutorial, I’ll show you how it works on macOS (or any supported Unix-based system).

Getting Started with dotnet app run.cs

First, install the .NET 10 SDK.

On macOS, you can use Homebrew:

brew install junian/dotnet/dotnet-sdk@10.0

Create a new file and make it executable:

How to Uninstall Old .NET SDK and Runtime Versions on macOS

author@junian.dev (Junian Triajianto) — Mon, 08 Sep 2025 09:43:28 +0700

If you’re a .NET developer using macOS, you might not realize that old versions of the .NET SDK and Runtime can take up valuable storage space. When you install a new .NET version, previous versions are usually left behind. This is often helpful for testing different .NET versions side by side.

Fortunately, you can easily identify all installed .NET versions on macOS using Terminal.

Check Installed .NET SDKs and Runtimes

First, let’s see which .NET SDKs and Runtimes are installed on your system. Run the following command:

WinForms 32-bit 'Designer Could Not Be Shown' Issue

author@junian.dev (Junian Triajianto) — Sun, 09 Mar 2025 10:30:40 +0700

When I was working on a company WinForms project in Visual Studio, I encountered the following error:

The designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file: frmDataEditor — The base class ‘Client.Forms’ could not be loaded. Ensure the assembly has been referenced and that all projects have been built.

Here’s the complete Stack Trace:

Solving the Xamarin.Forms iOS 'Could Not Load the Framework IDEDistribution' Issue

author@junian.dev (Junian Triajianto) — Thu, 13 Feb 2025 16:03:36 +0700

Xamarin.Forms is deprecated as of May 2024. I get it. But some of us are still trying to maintain legacy Xamarin projects.

Not in the mood for reading? Watch the video instead.

It’s 2025, and I tried to run a Xamarin.Forms iOS project with the latest Xcode version on macOS. It failed with the following error message.

error HE0004: Could not load the framework ‘IDEDistribution’ (path: /Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution): dlopen(/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution, 0x0001): Library not loaded: @rpath/AppThinning.framework/Versions/A/AppThinning Referenced from: <6F88EF9E-AE57-3231-9DD6-36E9CC59D914> /Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/IDEDistribution Reason: tried: ‘/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/Frameworks/AppThinning.framework/Versions/A/AppThinning’ (no such file), ‘/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/Frameworks/AppThinning.framework/Versions/A/AppThinning’ (no such file), ‘/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/Frameworks/AppThinning.framework/Versions/A/AppThinning’ (no such file), ‘/Applications/Xcode.app/Contents/SharedFrameworks/IDEDistribution.framework/Versions/A/Frameworks/AppThinning.framework/Versions/A/AppThinning’ (no such file), ‘/Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/lib/mlaunch/mlaunch.app/Contents/MonoBundle/AppThinning.framework/Versions/A/AppThinning’ (no such file)

Fizz Buzz - LeetCode in C#

author@junian.dev (Junian Triajianto) — Thu, 14 Nov 2024 12:01:57 +0700

The Fizz Buzz problem is a classic exercise that is often used to teach basic programming concepts such as loops and conditionals.

In this article, I’ll show you my attempt to solve this problem.

Problem Description

Given an integer n, return a string array answer (1-indexed) where:

answer[i] == "FizzBuzz" if i is divisible by 3 and 5.
answer[i] == "Fizz" if i is divisible by 3.
answer[i] == "Buzz" if i is divisible by 5.
answer[i] == i (as a string) if none of the above conditions are true.

Example 1:

Input: n = 3
Output: ["1","2","Fizz"]

Example 2:

Input: n = 5
Output: ["1","2","Fizz","4","Buzz"]

Example 3:

Input: n = 15
Output: ["1","2","Fizz","4","Buzz","Fizz","7","8","Fizz","Buzz","11","Fizz","13","14","FizzBuzz"]

Constraints:

1 <= n <= 10⁴

Intuition

When breaking down the problem, the task is to iterate through a sequence of numbers while applying simple divisibility rules to determine the correct output for each number.

Palindrome Number - LeetCode in C#

author@junian.dev (Junian Triajianto) — Sun, 10 Nov 2024 17:03:55 +0700

Problem

Given an integer x, return true if x is a palindrome , and false otherwise.

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

Example 2:

Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

Constraints:

Remove Duplicates From Sorted Array - LeetCode in C#

author@junian.dev (Junian Triajianto) — Sat, 09 Nov 2024 14:46:13 +0700

Problem Description

Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same. Then return the number of unique elements in nums.

Consider the number of unique elements of nums to be k, to get accepted, you need to do the following things:

Change the array nums such that the first k elements of nums contain the unique elements in the order they were present in nums initially. The remaining elements of nums are not important as well as the size of nums.
Return k.

Custom Judge:

Two Sum - LeetCode in C# - Hash Table Solution

author@junian.dev (Junian Triajianto) — Fri, 08 Nov 2024 18:51:32 +0700

Problem

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

You can return the answer in any order.

Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].

Example 2:

Two Sum - LeetCode in C# - Brute force approach

author@junian.dev (Junian Triajianto) — Fri, 08 Nov 2024 13:39:47 +0700

You might want to read the Hash Table solution. It’s better.

Intuition

When I first encountered the Two Sum problem, my initial thought was to check each possible pair of numbers in the array. If a pair sums to the target value, then that would be our solution.

This brute force method should work, but intuitively, I thought there might be more efficient ways.

However, starting with the simplest idea often helps to understand the problem better and refine the approach.

Folder Browser Dialog on Windows with C#

author@junian.dev (Junian Triajianto) — Sun, 05 May 2024 13:42:11 +0700

In this guide, I’ll walk you through the process of implementing a folder selection UI using C#.

In many applications, users need to specify a folder where certain files will be saved or retrieved. Providing a user-friendly way to select folders enhances the overall usability of your application.

To implement a folder selection dialog in C#, we’ll use the FolderBrowserDialog class provided by the .NET framework. This class allows users to browse and select folders from their file system with ease.

Can't Open Form [Design] View in WinForms Project

author@junian.dev (Junian Triajianto) — Sun, 05 May 2024 09:48:56 +0700

Have you ever been developing a WinForms project and encountered a situation where you couldn’t use the View Designer?

This problem can occur when you’re using the latest SDK-style project but are still targeting an older version of .NET, such as 4.8 or below.

Rest assured, you’re not alone. The solution is rather straightforward.

In Visual Studio, simply right-click on your project file and select Edit Project File.

Now, you just need to include a new ItemGroup for your Form files.

VSCode Avalonia Extension Download .NET Runtime Issue

author@junian.dev (Junian Triajianto) — Wed, 17 Apr 2024 16:08:38 +0700

So I want to start using AvaloniaUI on macOS, but suddenly it always happens.

AvaloniaTeam.vscode-avalonia requested to download the .NET Runtime. Downloading .NET version(s) 8.0.4~arm64 ….Error Failed to download .NET 8.0: Web Request to https://dot.net/v1/dotnet-install.sh Failed: n[r].split is not a function. Aborting. Please ensure that you are online.

To solve that, just open the VSCode settings.json and configure it with the following settings.

"dotnetAcquisitionExtension.existingDotnetPath": [
    {
        "extensionId": "ms-dotnettools.csharp",
        "path": "/usr/local/share/dotnet/dotnet"
    },
    {
        "extensionId": "ms-dotnettools.csdevkit", 
        "path": "/usr/local/share/dotnet/dotnet"
    },
    {
        "extensionId": "visualstudiotoolsforunity.vstuc", 
        "path": "/usr/local/share/dotnet/dotnet"
    },
    {
        "extensionId": "AvaloniaTeam.vscode-avalonia", 
        "path": "/usr/local/share/dotnet/dotnet"
    },
]

That’s it, now you can use AvaloniaUI on VSCode with auto-complete and everything.

Save C# Image Object into Oracle BLOB

author@junian.dev (Junian Triajianto) — Wed, 13 Nov 2019 06:00:13 +0700

Some of my friends requested me to make a tutorial about the Oracle database and C#. This time, I’d like to share about how to Save Image or Picture from C# Object into Oracle BLOB Type. It’s very easy if you know the trick.

To make the tutorial simple, let’s assume a table with 1 field. It’ll be used to store a collection of photos.

CREATE TABLE PHOTO 
(
  PHOTO_BIN BLOB 
);

Next, open or create a new C# project. Add Oracle.ManagedDataAccess NuGet package to your project.

Fixing 'Managed Debugging Assistant LoaderLock' Error

author@junian.dev (Junian Triajianto) — Fri, 14 Sep 2018 12:36:45 +0700

Recently I’ve been doing some tasks that require me to build OpenDental from source code. It is a Dental Practice software with some graphical features. They are developing those graphical features by using using DirectX API.

This software have been developed since a long time ago so I expect that there will be some incompatibility if I’m using latest Visual Studio. In my case, I use Visual Studio 2017 v15.8.4 to compile and run the program.

Complete C# String Hash Functions

author@junian.dev (Junian Triajianto) — Fri, 14 Sep 2018 06:34:40 +0700

For a while I’ve been seeing my blog traffic and surprisingly there are some of you are landed here by searching about MD5 string hash in C#, specifically used for storing password. I wrote the first draft of that tutorial when I was still in college while learning C# as a student, so it’s really old tutorial.

As we know, MD5 isn’t recommended anymore because it is designed to be very fast and efficient. By using modern computers and techniques, it is possible to “brute force” the hash output, in order to retrieve the original input. Because of this, many security experts suggest not to use it for password hashing.

Solving Sharepoint ClientContext Socket Exception in C#

author@junian.dev (Junian Triajianto) — Fri, 07 Sep 2018 06:39:53 +0700

So, you’ve been writing a Sharepoint client application and it’s running just fine. After several weeks or months, you noticed some errors were showing up. If you see a lot of SocketException error messages like following snippet, then this article is for you.

System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: Only one usage of each socket address (protocol/network address/port) is normally permitted 127.0.0.1:443
     at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
     at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)

In my previous article about Sharepoint CSOM Socket Exception, I wrote about on how to solve this issue by editing some registry values. I did it and worked beautifully, but only for several days.

Fullscreen Video Background Control for Xamarin.Forms

author@junian.dev (Junian Triajianto) — Fri, 03 Mar 2017 07:17:00 +0000

One of the cool trend on mobile UI I’ve seen a lot is using video as View background. You can see it on some big mobile app products like Tumblr, Spotify, and Vine. As you can see, they have this cool Home View with sign in and sing up button with video playing in background. This feature is so cool and can make your app look more professional.

This time, I’ll show you how to implement it in Xamarin.Forms app. All we need is to implement two custom renderers for Android and iOS each.

🏆 Best Mobile Article of March 2017 : Second Prize at CodeProject.

Creating Video View Control for Xamarin.Forms

Let’s create a new Xamarin.Forms PCL project first and name it BackgroundVideo. Now let’s head to the PCL library and create a new class called Video inherited from Xamarin.Forms.View.

using System;  
using Xamarin.Forms;  
  
namespace BackgroundVideo.Controls  
{  
  public class Video : View  
  {  
  }  
}

For the sake of the tutorial, we’re going to make this control with simple requirements.

We need a bindable property to point which video to be displayed. I’m going to call it Source property. It’s a string to locate which video file to be played. On iOS, Source property is relative to Resources directory as for Android, it is relative to Assets directory.

public static readonly BindableProperty SourceProperty =  
    BindableProperty.Create(  
    nameof(Source),  
    typeof(string),  
    typeof(Video),  
    string.Empty,  
    BindingMode.TwoWay);  
  
public string Source  
{  
    get { return (string)GetValue(SourceProperty); }  
    set { SetValue(SourceProperty, value); }  
}

Next thing we need is a boolean to define if we want the video in loop or not. Let’s call this property Loop. By default, I set this value as true so when you set a video Source property, it would be looped by default.

Finally, we’re going to need a callback fired when video is finished. For simplicity, I use Action class called OnFinishedPlaying. You can modify it to event or anything you comfortable with.

public static readonly BindableProperty LoopProperty =  
    BindableProperty.Create(  
    nameof(Loop),  
    typeof(bool),  
    typeof(Video),  
    true,  
    BindingMode.TwoWay);  
  
public bool Loop  
{  
    get { return (bool)GetValue(LoopProperty); }  
    set { SetValue(LoopProperty, value); }  
}  
  
public Action OnFinishedPlaying { get; set; }

After we created this class, next thing to do is to implement custom renderers for both iOS and Android.

Video View Control iOS Custom Renderer

First thing to do is to create a custom renderer class called VideoRenderer inherited from ViewRenderer<Video, UIView>. The idea is to use iOS native video player with the help of MPMoviePlayerController class and set its native control to our Video custom view. Also we’re going to need an NSObject to listen the event from video player wether it is ended or not.

using System;  
using System.IO;  
using BackgroundVideo.Controls;  
using BackgroundVideo.iOS.Renderers;  
using Foundation;  
using MediaPlayer;  
using UIKit;  
using Xamarin.Forms;  
using Xamarin.Forms.Platform.iOS;  
  
[assembly: ExportRenderer(typeof(Video), typeof(VideoRenderer))]  
namespace BackgroundVideo.iOS.Renderers  
{  
  public class VideoRenderer : ViewRenderer<Video, UIView>  
  {  
    MPMoviePlayerController videoPlayer;  
    NSObject notification = null;  
  }  
}

To start iOS video player, we need to check wether the video from Source property exists in Resources budnle or not. If it doesn’t exist, we’ll display an empty view.

If the video file exists, we need to create MPMoviePlayerController and parse the location of the video file as NSUrl. To make our custom control clear, without border or anything, we need to set ControlStyle to MPMovieControlStyle.None and background color to UIColor.Clear.

Also, we probably will have one video file for any resolution. You don’t want it to look stretched on some device, right? To make the video resolution looks consistent, we need to set video player ScalingMode to MPMovieScalingMode.AspectFill.

We also have this Loop property to define wether the video playing will be looped or not. To set it to loop, we need to change video player RepeatMode to MPMovieRepeatMode.One. Otherwise, set it to MPMovieRepeatMode.None.

Finally, to make video player play the file, we call PrepareToPlay() function. To display the video to our custom control, we need to use SetNativeControl() function.

void InitVideoPlayer()  
{  
    var path = Path.Combine(NSBundle.MainBundle.BundlePath, Element.Source);  
  
    if (!NSFileManager.DefaultManager.FileExists(path))  
    {  
      Console.WriteLine("Video not exist");  
      videoPlayer = new MPMoviePlayerController();  
      videoPlayer.ControlStyle = MPMovieControlStyle.None;  
      videoPlayer.ScalingMode = MPMovieScalingMode.AspectFill;  
      videoPlayer.RepeatMode = MPMovieRepeatMode.One;  
      videoPlayer.View.BackgroundColor = UIColor.Clear;  
      SetNativeControl(videoPlayer.View);  
      return;  
    }  
  
    // Load the video from the app bundle. 
    NSUrl videoURL = new NSUrl(path, false);  
  
    // Create and configure the movie player. 
    videoPlayer = new MPMoviePlayerController(videoURL);  
  
    videoPlayer.ControlStyle = MPMovieControlStyle.None;  
    videoPlayer.ScalingMode = MPMovieScalingMode.AspectFill;  
    videoPlayer.RepeatMode = Element.Loop ? MPMovieRepeatMode.One : MPMovieRepeatMode.None;  
    videoPlayer.View.BackgroundColor = UIColor.Clear;  
    foreach (UIView subView in videoPlayer.View.Subviews)  
    {  
      subView.BackgroundColor = UIColor.Clear;  
    }  
  
    videoPlayer.PrepareToPlay();  
    SetNativeControl(videoPlayer.View);  
}

The rest of the code is to override OnElementChanged and OnElementPropertyChanged function so it can be functionally working from Xamarin.Forms project. Under OnElementChanged, we need to listen to video player playback finish event and invoke OnFinishedPlaying action. The following snippet is the simplest code necessary to make it work.

protected override void OnElementChanged(ElementChangedEventArgs<Video> e)  
{  
    base.OnElementChanged(e);  
  
    if (Control == null)  
    {  
      InitVideoPlayer();  
    }  
    if (e.OldElement != null)  
    {  
      // Unsubscribe  
      notification?.Dispose();  
    }  
    if (e.NewElement != null)  
    {  
      // Subscribe  
      notification = MPMoviePlayerController.Notifications.ObservePlaybackDidFinish((sender, args) =>  
      {  
        /* Access strongly typed args */  
        Console.WriteLine("Notification: {0}", args.Notification);  
        Console.WriteLine("FinishReason: {0}", args.FinishReason);  
  
        Element?.OnFinishedPlaying?.Invoke();  
      });  
    }  
}  
  
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)  
{  
    base.OnElementPropertyChanged(sender, e);  
    if (Element == null || Control == null)  
      return;  
  
    if (e.PropertyName == Video.SourceProperty.PropertyName)  
    {  
      InitVideoPlayer();  
    }  
    else if (e.PropertyName == Video.LoopProperty.PropertyName)  
    {  
      var liveImage = Element as Video;  
      if (videoPlayer != null)  
        videoPlayer.RepeatMode = Element.Loop ? MPMovieRepeatMode.One : MPMovieRepeatMode.None;  
    }  
}

Now that iOS implementation is completed, let’s head to our Android project.

Video View Custom Renderer for Android

Create a new custom renderer on Android project and let’s name it VideoRenderer, too. We’ll inherit this renderer with ViewRenderer<Video, FrameLayout>, meaning it will be displayed as FrameLayout in native Android control.

One thing that made Android implementation a bit complicated is that we need two kind of views if you want to cover old Android versions. If you just want to cover modern Android OS from Ice Cream Sandwich or more, you can just focus on TextureView implementation, if not you’ll also need to implement it using VideoView.

Please note that VideoView implementation here is not optimal. Maybe you’ll notice some flickering. That’s why I add view called _placeholder. This is just an empty view. It’ll be displayed when no video playing or when in video source changed transition. If the video file ready to play and display, _placeholder will be hidden.

using System;  
using Android.Graphics;  
using Android.Graphics.Drawables;  
using Android.Media;  
using Android.OS;  
using Android.Runtime;  
using Android.Views;  
using Android.Widget;  
using BackgroundVideo.Controls;  
using BackgroundVideo.Droid.Renderers;  
using Xamarin.Forms;  
using Xamarin.Forms.Platform.Android;  
  
[assembly: ExportRenderer(typeof(Video), typeof(VideoRenderer))]  
namespace BackgroundVideo.Droid.Renderers  
{  
  public class VideoRenderer : ViewRenderer<Video, FrameLayout>,  
                 TextureView.ISurfaceTextureListener,  
                 ISurfaceHolderCallback  
  {  
    private bool _isCompletionSubscribed = false;  
  
    private FrameLayout _mainFrameLayout = null;  
  
    private Android.Views.View _mainVideoView = null;  
    private Android.Views.View _placeholder = null;  
  
  }  
}

Now before we thing about what video container to use, we need to implement the video player itself. Android already provide us with their MediaPlayer class. We’ll need to use this object and make sure it only created once. We can reuse the same object if we change the video source.

We need to set Completion event to implement our OnFinishedPlaying callback. We also need to set Looping property to our custom Loop property.

There is one thing that different from our iOS implementation, there is no easy property set to display video resolution as aspect fill! That means we need to implement our own method into custom function called AdjustTextureViewAspect(). This function will be called on VideoSizeChanged callback. We’ll talk about this implementation later.

private MediaPlayer _videoPlayer = null;  
internal MediaPlayer VideoPlayer  
{  
  get  
  {  
    if (_videoPlayer == null)  
    {  
      _videoPlayer = new MediaPlayer();  
  
      if (!_isCompletionSubscribed)  
      {  
        _isCompletionSubscribed = true;  
        _videoPlayer.Completion += Player_Completion;  
      }  
  
      _videoPlayer.VideoSizeChanged += (sender, args) =>  
      {  
        AdjustTextureViewAspect(args.Width, args.Height);  
      };  
  
      _videoPlayer.Info += (sender, args) =>  
      {  
        Console.WriteLine("onInfo what={0}, extra={1}", args.What, args.Extra);  
        if (args.What == MediaInfo.VideoRenderingStart)  
        {  
          Console.WriteLine("[MEDIA_INFO_VIDEO_RENDERING_START] placeholder GONE");  
          _placeholder.Visibility = ViewStates.Gone;  
        }  
      };  
  
      _videoPlayer.Prepared += (sender, args) =>  
      {  
        _mainVideoView.Visibility = ViewStates.Visible;  
        _videoPlayer.Start();  
        if (Element != null)  
          _videoPlayer.Looping = Element.Loop;  
      };  
    }  
  
    return _videoPlayer;  
  }  
}  
  
private void Player_Completion(object sender, EventArgs e)  
{  
  Element?.OnFinishedPlaying?.Invoke();  
}

Now that we have our video player object, next thing is to create function that play video from Source property. Please remember that video file on Android need to be stored under Assets directory. We can open this file by using Assets.OpenFd(fullPath) function.

If the file doesn’t exist, it’ll throw Java.IO.IOException. That means we don’t need to display anything on our video container.

If the file exists, we just need to reset our video player, then set data source based on previous step. We can’t just play the video directly, so we need to prepare it first. When preparation complete, it’ll trigger Prepared event and display the video to one of our implemented video view from previous step.

private void PlayVideo(string fullPath)  
{  
  Android.Content.Res.AssetFileDescriptor afd = null;  
  
  try  
  {  
    afd = Context.Assets.OpenFd(fullPath);  
  }  
  catch (Java.IO.IOException ex)  
  {  
    Console.WriteLine("Play video: " + Element.Source + " not found because " + ex);  
    _mainVideoView.Visibility = ViewStates.Gone;  
  }  
  catch (Exception ex)  
  {  
    Console.WriteLine("Error openfd: " + ex);  
    _mainVideoView.Visibility = ViewStates.Gone;  
  }  
  
  if (afd != null)  
  {  
    Console.WriteLine("Lenght " + afd.Length);  
    VideoPlayer.Reset();  
    VideoPlayer.SetDataSource(afd.FileDescriptor, afd.StartOffset, afd.Length);  
    VideoPlayer.PrepareAsync();  
  }  
}

As previously mentioned, Android doesn’t provide us easy property to scale our video to aspect fill. You know it yourself that Android devices have so many screen resolution so keep the video like it is is not an option. We need to scale it properly so it won’t look stretched.

Good news is, we can do that if we use TextureView. Bad news is for now I don’t know how to implement it with VideoView. But it’s better than nothing right?

The idea to make video scale properly is to use matrix to scale the content of TextureView. It is scaled up or down based on video size and view size. Then, after it’s scaled, it is positioned at the center of the view.

private void AdjustTextureViewAspect(int videoWidth, int videoHeight)  
{  
  if (!(_mainVideoView is TextureView))  
    return;  
  
  if (Control == null)  
    return;  
  
  var control = Control;  
  
  var textureView = _mainVideoView as TextureView;  
  
  var controlWidth = control.Width;  
  var controlHeight = control.Height;  
  var aspectRatio = (double)videoHeight / videoWidth;  
  
  int newWidth, newHeight;  
  
  if (controlHeight <= (int)(controlWidth * aspectRatio))  
  {  
    // limited by narrow width; restrict height  
    newWidth = controlWidth;  
    newHeight = (int)(controlWidth * aspectRatio);  
  }  
  else  
  {  
    // limited by short height; restrict width  
    newWidth = (int)(controlHeight / aspectRatio);  
    newHeight = controlHeight;  
  }  
  
  int xoff = (controlWidth - newWidth) / 2;  
  int yoff = (controlHeight - newHeight) / 2;  
  
  Console.WriteLine("video=" + videoWidth + "x" + videoHeight +  
      " view=" + controlWidth + "x" + controlHeight +  
      " newView=" + newWidth + "x" + newHeight +  
      " off=" + xoff + "," + yoff);  
  
  var txform = new Matrix();  
  textureView.GetTransform(txform);  
  txform.SetScale((float)newWidth / controlWidth, (float)newHeight / controlHeight);  
  txform.PostTranslate(xoff, yoff);  
  textureView.SetTransform(txform);  
}

As mentioned earlier, if we want to support a wide range of Android OS, we need to implement it into TextureView and VideoView. This will be implemented under OnElementChanged function. Both implementation have some same properties. We will make their Background color to transparent and layout parameters to match parent. This way it won’t have any color to display when there is no video, and it’ll fill entire container.

Following snippet is how to implement it on our Video custom renderer. You see it’s similar with our iOS implementation, except for container creation and video playing.

protected override void OnElementChanged(ElementChangedEventArgs<Video> e)  
{  
  base.OnElementChanged(e);  
  
  if (Control == null)  
  {  
    _mainFrameLayout = new FrameLayout(Context);  
  
    _placeholder = new Android.Views.View(Context)  
    {  
      Background = new ColorDrawable(Xamarin.Forms.Color.Transparent.ToAndroid()),  
      LayoutParameters = new LayoutParams(  
        ViewGroup.LayoutParams.MatchParent,  
        ViewGroup.LayoutParams.MatchParent),  
    };  
  
    if (Build.VERSION.SdkInt < BuildVersionCodes.IceCreamSandwich)  
    {  
      Console.WriteLine("Using VideoView");  
  
      var videoView = new VideoView(Context)  
      {  
        Background = new ColorDrawable(Xamarin.Forms.Color.Transparent.ToAndroid()),  
        Visibility = ViewStates.Gone,  
        LayoutParameters = new LayoutParams(  
          ViewGroup.LayoutParams.MatchParent,  
          ViewGroup.LayoutParams.MatchParent),  
      };  
  
      ISurfaceHolder holder = videoView.Holder;  
      if (Build.VERSION.SdkInt < BuildVersionCodes.Honeycomb)  
      {  
        holder.SetType(SurfaceType.PushBuffers);  
      }  
      holder.AddCallback(this);  
  
      _mainVideoView = videoView;  
    }  
    else  
    {  
      Console.WriteLine("Using TextureView");  
  
      var textureView = new TextureView(Context)  
      {  
        Background = new ColorDrawable(Xamarin.Forms.Color.Transparent.ToAndroid()),  
        Visibility = ViewStates.Gone,  
        LayoutParameters = new LayoutParams(  
          ViewGroup.LayoutParams.MatchParent,  
          ViewGroup.LayoutParams.MatchParent),  
      };  
  
      textureView.SurfaceTextureListener = this;  
  
      _mainVideoView = textureView;  
    }  
  
    _mainFrameLayout.AddView(_mainVideoView);  
    _mainFrameLayout.AddView(_placeholder);  
  
    SetNativeControl(_mainFrameLayout);  
  
    PlayVideo(Element.Source);  
  }  
  if (e.OldElement != null)  
  {  
    // Unsubscribe  
    if (_videoPlayer != null && _isCompletionSubscribed)  
    {  
      _isCompletionSubscribed = false;  
      _videoPlayer.Completion -= Player_Completion;  
    }  
  }  
  if (e.NewElement != null)  
  {  
    // Subscribe  
    if (_videoPlayer != null && !_isCompletionSubscribed)  
    {  
      _isCompletionSubscribed = true;  
      _videoPlayer.Completion += Player_Completion;  
    }  
  }  
}  
  
protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)  
{  
  base.OnElementPropertyChanged(sender, e);  
  if (Element == null || Control == null)  
    return;  
  
  if (e.PropertyName == Video.SourceProperty.PropertyName)  
  {  
    Console.WriteLine("Play video: " + Element.Source);  
    PlayVideo(Element.Source);  
  }  
  else if (e.PropertyName == Video.LoopProperty.PropertyName)  
  {  
    Console.WriteLine("Is Looping? " + Element.Loop);  
    VideoPlayer.Looping = Element.Loop;  
  }  
}

Since we’re using TextureView and VideoView, there is some function from interfaces need to be implemented. One of them is to remove video when texture or surface is destroyed. To do that, we’re going to need to set _placeholder visibility to visible.

private void RemoveVideo()  
{  
  _placeholder.Visibility = ViewStates.Visible;  
}

When using TextureView, we need to implement TextureView.ISurfaceTextureListener interface. We set video player’s surface when texture available and hide it when texture destroyed. Following snippet shows you how to implement it.

#region Surface Texture Listener  
  
public void OnSurfaceTextureAvailable(SurfaceTexture surface, int width, int height)  
{  
  Console.WriteLine("Surface.TextureAvailable");  
  VideoPlayer.SetSurface(new Surface(surface));  
}  
  
public bool OnSurfaceTextureDestroyed(SurfaceTexture surface)  
{  
  Console.WriteLine("Surface.TextureDestroyed");  
  RemoveVideo();  
  return false;  
}  
  
public void OnSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height)  
{  
  Console.WriteLine("Surface.TextureSizeChanged");  
}  
  
public void OnSurfaceTextureUpdated(SurfaceTexture surface)  
{  
  Console.WriteLine("Surface.TextureUpdated");  
}  
  
#endregion

When using VideoView, we need to implement ISurfaceHolderCallback interface. Similar with TextureView, we set video player’s display when surface created and hide it when surface destroyed. The complete implementation of this interface can be see on following snippet.

#region Surface Holder Callback  
  
public void SurfaceChanged(ISurfaceHolder holder, [GeneratedEnum] Format format, int width, int height)  
{  
  Console.WriteLine("Surface.Changed");  
}  
  
public void SurfaceCreated(ISurfaceHolder holder)  
{  
  Console.WriteLine("Surface.Created");  
  VideoPlayer.SetDisplay(holder);  
}  
  
public void SurfaceDestroyed(ISurfaceHolder holder)  
{  
  Console.WriteLine("Surface.Destroyed");  
  RemoveVideo();  
}  
  
#endregion

That’s all we need for Android. Now that we all have everything needed, we can test this control to Xamarin.Forms Page.

Testing to Xamarin.Forms Page

Before we create a test page, I recommend you to prepare your own video file. It is recommended as vertical video so a lot of space won’t be wasted.

But, if you don’t have any video to test, don’t worry. You can download free videos to use from Coverr. They don’t have any vertical videos, we can still use it. You can either crop it into vertical video or you can just use it as it is since we already handle scaling to aspect fill on our code.

So use any video you like. I recommend any file as long as it’s mp4 video with h264 encoding. In this tutorial, I use video from Coverr called Orchestra. You can download it from here.

NOTE: For some Android and iOS devices, especially the old products, they probably can’t play some mp4 files. This is mostly caused by not-supported baseline profile. To fix that, you can re-encode the video using a tool like ffmpeg and change its baseline profile based on your preferences. See following table to check baseline profile compatibility with iOS. See Supported Media Formats from official Android guide, too.

Profile	Level	Devices	Options
Baseline	3.0	All devices	`-profile:v baseline -level 3.0`
Baseline	3.1	iPhone 3G and later, iPod touch 2nd generation and later	`-profile:v baseline -level 3.1`
Main	3.1	iPad (all versions), Apple TV 2 and later, iPhone 4 and later	`-profile:v main -level 3.1`
Main	4.0	Apple TV 3 and later, iPad 2 and later, iPhone 4s and later	`-profile:v main -level 4.0`
High	4.0	Apple TV 3 and later, iPad 2 and later, iPhone 4s and later	`-profile:v high -level 4.0`
High	4.1	iPad 2 and later, iPhone 4s and later, iPhone 5c and later	`-profile:v high -level 4.1`
High	4.2	iPad Air and later, iPhone 5s and later	`-profile:v high -level 4.2`

h.264 baseline profiles for iOS. Source: ffmpeg

After you get your video file, place it to the folders for each OS. On Android, you should put it under Assets directory. On iOS, you should put it under Resources directory. For this tutorial I put the file under Assets/Videos on Android and Resources/Videos on iOS.

Once you put them all to correct folder, we need to create our Page on Xamarin.Forms PCL project.

This is a simple page with smallest components. We’ll create a Home Page, with video background, two text boxes for username and password, and to buttons for sign in and sign up. There is no logic in this page, I just want to show you how to make a beautiful home page.

For better controls placement, I use Grid as container. See following snippet for the complete XAML.

<?xml version="1.0" encoding="utf-8"?>  
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"   
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"   
    xmlns:local="clr-namespace:BackgroundVideo"   
    xmlns:controls="clr-namespace:BackgroundVideo.Controls"   
    x:Class="BackgroundVideo.BackgroundVideoPage">  
  <Grid Padding="0" RowSpacing="0" ColumnSpacing="0">  
    <controls:Video x:Name="video" Source="Videos/Orchestra.mp4" Loop="true"   
      HorizontalOptions="Fill" VerticalOptions="Fill" />  
    <StackLayout VerticalOptions="Center" HorizontalOptions="FillAndExpand" Padding="20,10,10,20">  
      <Entry Placeholder="username" FontSize="Large"   
        FontFamily="Georgia" HeightRequest="50">  
        <Entry.PlaceholderColor>  
          <OnPlatform x:TypeArguments="Color" Android="Silver" />  
        </Entry.PlaceholderColor>  
        <Entry.TextColor>  
          <OnPlatform x:TypeArguments="Color" Android="White" />  
        </Entry.TextColor>  
      </Entry>  
      <Entry Placeholder="password" FontSize="Large"   
        FontFamily="Georgia" HeightRequest="50" IsPassword="true">  
        <Entry.PlaceholderColor>  
          <OnPlatform x:TypeArguments="Color" Android="Silver" />  
        </Entry.PlaceholderColor>  
        <Entry.TextColor>  
          <OnPlatform x:TypeArguments="Color" Android="White" />  
        </Entry.TextColor>  
      </Entry>  
      <BoxView Color="Transparent" HeightRequest="10" />  
      <Button Text="sign in" BackgroundColor="#3b5998" TextColor="#ffffff"   
        FontSize="Large" />  
      <Button Text="sign up" BackgroundColor="#fa3c4c" TextColor="#ffffff"   
        FontSize="Large" />  
    </StackLayout>  
  </Grid>  
</ContentPage>

That’s it. If you don’t want the video to be looped, just change its Loop property. If you want to do something when video ended, just set OnFinishedPlaying from C# code. Now let’s see how it runs.

See it in Action

If you set everything correctly, The following figure is how it run on iOS device or emulator. As you can see, there are two text boxes and two buttons. The video is playing as the page background smoothly.

Xamarin iOS Background Video Demo

Similar with iOS version, the following animated gif image shows how it looks on Android device or emulator. See that text box style difference from iOS version. But let’s care about it later, the point is video background consistently work just like iOS.

Xamarin Android Background Video Demo

All you need to do the rest is to make styling more consistent through any platforms.

Summary

Once again, all I can say is you can make any cross platform control you want by using Custom Renderer. As long as you understand how to code in native language (well, you can Google it though), you can create anything.

As for performance, I believe I said it earlier, you probably see some flickering on old Android devices. For now I don’t have any idea to optimize it.

If you have any idea and suggestion, feel free to leave a comment below.

You can download completed project on GitHub.

References

Encode/H.264 – FFmpeg
Play video in background (like spotify) using xamarin forms and android renderer - Xamarin Community Forums
How to avoid flickering and black screen issues when using VideoView? | Bright Inventions
iOS Video Backgrounds – Kai Schaller – Medium

Simple Custom Fonts Helper in Xamarin.Forms for Android

author@junian.dev (Junian Triajianto) — Thu, 09 Feb 2017 07:33:00 +0000

When creating a mobile app, we want it to look great. Not just by design but also typography great. Xamarin.Forms already provide custom font mechanism. But I don’t see it efficient enough because it has to be declared differently for each platform. Look at the example snippet below.

<Label Text="Hello Forms with XAML">  
    <Label.FontFamily>  
        <OnPlatform x:TypeArguments="x:String">  
            <OnPlatform.iOS>Oswald-Regular</OnPlatform.iOS>  
            <OnPlatform.Android>Oswald-Regular.ttf#Oswald-Regular</OnPlatform.Android>  
            <OnPlatform.WinPhone>Assets/Fonts/Oswald-Regular.ttf#Oswald</OnPlatform.WinPhone>  
        </OnPlatform>  
    </Label.FontFamily>  
</Label>

See that how for each platform it’s different string. On iOS, you just need to set font name. As for Android and WinPhone you need to declare path to font file and font name. All I want to do is to just call the font name like iOS does and for every platform it’ll render correctly like following snippet.

How To Play Audio Files in Xamarin.Forms

author@junian.dev (Junian Triajianto) — Wed, 08 Feb 2017 12:25:00 +0000

Audio, sound, or music can be essential part of mobile apps. Unfortunately, Xamarin.Forms doesn’t support this directly from their API. But of course, it can be implemented easily by using DependencyService.

This time I’ll show you how to implement this Audio Player in Xamarin.Forms with the help of DependencyService. Also, I’ll show you how to integrate it using simple MVVM Pattern.

First thing first, create a new Xamarin.Forms Solution.

Use Portable Class library and XAML for user interface. Let’s name this solution AudioPlayer. Now that we’ve created a new solution, we’ll have three projects: Portable Library, iOS, and Android. We’ll implement one by one starting from our core Portable Library.

Running Your First ASP.NET Core Web App with MySQL on Ubuntu 16.04

author@junian.dev (Junian Triajianto) — Tue, 24 Jan 2017 09:15:00 +0000

Since Microsoft open sourcing their .NET Platform, which is called .NET Core, they stole my attention again. I always love using .NET Framework. I develop desktop apps using it. I develop mobile apps using Xamarin. But I rarely use its web platform for one simple reason, it requires Windows-based Server to run.

Now that Microsoft and community actively develop its framework for cross-platform environment, I stumble upon and see the latest stable build which is version 1.1. I read their blog and found out about news that ASP.NET Core 1.1 with Kestrel was ranked as the fastest mainstream fullstack web framework in the TechEmpower plaintext benchmark. That’s such a nice claim and gave me attention to try their product.

Camera Face Detection in C# using Emgu CV and WPF

author@junian.dev (Junian Triajianto) — Thu, 29 Dec 2016 09:49:00 +0000

Hi there, this is a new tutorial category in my blog. It’s Computer Vision. In this blog, I’d like to show you something cool. It’s how to perform Face Detection using your camera or Webcam. You’ll see how your application can detect faces from a captured image. Curious about it? Let’s take a look how to do that.

This what you need to follow this tutorial:

Microsoft Visual Studio 2010. Or if you don’t have one, you can use 2008 version.
Emgu CV (OpenCV in .NET). You can download the latest version in this link: www.emgu.com/wiki/index.php/Main_Page and follow the installation instruction.
Basic Knowledge of C# Programming.
Familiar in WPF Development.

After you’ve got what you need, it’s time to rock!

Load External Image into WPF using OpenFileDialog

author@junian.dev (Junian Triajianto) — Tue, 13 Dec 2016 13:31:00 +0000

This is my first time I made a tutorial about WPF. I don’t think it’s a new technique, but I just want to share what I learned at home. I assume that you understand WPF a little bit. In this tutorial I’d like to show you how to load external image into WPF using OpenFileDialog.

Step 1

Create a new WPF Project, File → New → Project… and chose WPF Application (by the way, I’m using Visual Studio 2008 in this tutorial). You’ll see an empty window called Window1.xaml.

Password Encryption using MD5 Hash Algorithm in C#

author@junian.dev (Junian Triajianto) — Thu, 08 Dec 2016 09:57:00 +0000

Update (Sep 14, 2018): The new complete string hash algorithms in C# tutorial is available. I would suggest not to use MD5 anymore, because it’s not safe and easily collide. But I’ll leave the original tutorial here for educational purpose.

It’s really bad if someone knew your password. As a software developer, we have an ethic that we also don’t want to see other’s password. Which mean, storing password in a plain text is a nope.

How To Make A 2D Animation using Timer with C++ .NET

author@junian.dev (Junian Triajianto) — Tue, 06 Dec 2016 21:09:00 +0000

On my last post (How To Draw 2D Primitive Objects on Windows Forms Application using C++ .NET), we’ve learned about how to draw some 2D objects on Form and Panel. That’s not difficult right? But now, in this post, we’ll learn about how to move that objects. Of course it’ll be very boring if that objects didn’t move. So, let’s get started! Don’t forget that I’m using Microsoft Visual Studio 2008 Professional Edition in this tutorial.

How To Draw 2D Primitive Objects with C++ .NET

author@junian.dev (Junian Triajianto) — Thu, 01 Dec 2016 20:47:00 +0000

First of all, I’d like to present my first tutorial about C++ / CLI CLR .NET Programming. This time it’s about Graphical User Interface in C++ .NET (in this case, I don’t want to use native C++). Okay, I assume that you have a little knowledge about C++ .NET GUI and of course, I also assume that you understand how to program in C++ CLR behaviour. So, here we go the tutorial!