How to achieve single instance app in C#?

[JohnCido]

I want my app to have only one instance. I've gone through the doc and all I found are so many C++ examples and just explanations of differences between single instance and multiple instances app.

Is there a clear example to achieve it using clean C# codes and API interface in 1.0 preview 3?
And why not provide some C# examples in the doc?

[andrewleader]

Hi @JohnCido, we're working on improving the docs for single instancing, in the meantime here's a GIST that explains how to accomplish single instance in a C# app using 1.0 Preview 3: https://gist.github.com/andrewleader/5adc742fe15b06576c1973ea6e999552

Make sure you build/compile your app for x64, there's currently a known bug on x86.

[andrewleader]

We do have aspirations to make this easier in the future, however we don't have anything concrete planned to share around that at this time.

[KWodarczyk]

Can't we just use Application.Current.Exit(); instead of System.Diagnostics.Process.GetCurrentProcess().Kill(); ?

[KWodarczyk]

Also, instead of all that pinvoke stuff i just do m_window.DispatcherQueue.TryEnqueue(() => { m_window?.Activate(); }); and works, it this not allowed ?

[KWodarczyk]

My OnActivated method looks like this:

`private void OnActivated(object sender, AppActivationArguments e)
{
m_window.DispatcherQueue.TryEnqueue(() => { m_window?.Activate(); });

        //// Bring the window to the foreground... first get the window handle...
        //var hwnd = (Windows.Win32.Foundation.HWND)WinRT.Interop.WindowNative.GetWindowHandle(m_window);

        //// Restore window if minimized... requires Microsoft.Windows.CsWin32 NuGet package and a NativeMethods.txt file with ShowWindow method
        //Windows.Win32.PInvoke.ShowWindow(hwnd, Windows.Win32.UI.WindowsAndMessaging.SHOW_WINDOW_CMD.SW_RESTORE);

        //// And call SetForegroundWindow... requires Microsoft.Windows.CsWin32 NuGet package and a NativeMethods.txt file with SetForegroundWindow method
        //Windows.Win32.PInvoke.SetForegroundWindow(hwnd);
    }`

[hintsofttech]

single instance should mean single instance per user
because multiple users may run the app through remote desktop connections...