UWP文档笔记：控制台应用以及多实例

#include "pch.h"

using namespace winrt;

// This example code shows how you could implement the required main function
// for a Console UWP Application. You can replace all the code inside main
// with your own custom code.

int __cdecl main()
{
    // You can get parsed command-line arguments from the CRT globals.
    wprintf(L"Parsed command-line arguments:\n");
    for (int i = 0; i < __argc; i++)
    {
        wprintf(L"__argv[%d] = %S\n", i, __argv[i]);
    }

    // Keep the console window alive in case you want to see console output when running from within Visual Studio
	  wprintf(L"Press 'Enter' to continue: ");
    getchar();
}

<Package
  ...
  xmlns:desktop4="http://schemas.microsoft.com/appx/manifest/desktop/windows10/4" 
  xmlns:iot2="http://schemas.microsoft.com/appx/manifest/iot/windows10/2" 
  IgnorableNamespaces="uap mp uap5 desktop4 iot2">
  ...
  <Applications>
    <Application Id="App"
	  ...
      desktop4:Subsystem="console" 
      desktop4:SupportsMultipleInstances="true" 
      iot2:Subsystem="console" 
      iot2:SupportsMultipleInstances="true"  >
      ...
      <Extensions>
          <uap5:Extension 
            Category="windows.appExecutionAlias" 
            Executable="YourApp.exe" 
            EntryPoint="YourApp.App">
            <uap5:AppExecutionAlias desktop4:Subsystem="console">
              <uap5:ExecutionAlias Alias="YourApp.exe" />
            </uap5:AppExecutionAlias>
          </uap5:Extension>
      </Extensions>
    </Application>
  </Applications>
    ...
</Package>

<Package
  ...
  xmlns:desktop4="http://schemas.microsoft.com/appx/manifest/desktop/windows10/4"
  xmlns:iot2="http://schemas.microsoft.com/appx/manifest/iot/windows10/2"  
  IgnorableNamespaces="uap mp desktop4 iot2">
  ...
  <Applications>
    <Application Id="App"
      ...
      desktop4:SupportsMultipleInstances="true"
	  iot2:SupportsMultipleInstances="true">
      ...
    </Application>
  </Applications>
   ...
</Package>

public static class Program
{
    // This example code shows how you could implement the required Main method to
    // support multi-instance redirection. The minimum requirement is to call
    // Application.Start with a new App object. Beyond that, you may delete the
    // rest of the example code and replace it with your custom code if you wish.

    static void Main(string[] args)
    {
        // First, we'll get our activation event args, which are typically richer
        // than the incoming command-line args. We can use these in our app-defined
        // logic for generating the key for this instance.
        IActivatedEventArgs activatedArgs = AppInstance.GetActivatedEventArgs();

        // If the Windows shell indicates a recommended instance, then
        // the app can choose to redirect this activation to that instance instead.
        if (AppInstance.RecommendedInstance != null)
        {
            AppInstance.RecommendedInstance.RedirectActivationTo();
        }
        else
        {
            // Define a key for this instance, based on some app-specific logic.
            // If the key is always unique, then the app will never redirect.
            // If the key is always non-unique, then the app will always redirect
            // to the first instance. In practice, the app should produce a key
            // that is sometimes unique and sometimes not, depending on its own needs.
            string key = Guid.NewGuid().ToString(); // always unique.
                                                    //string key = "Some-App-Defined-Key"; // never unique.
            var instance = AppInstance.FindOrRegisterInstanceForKey(key);
            if (instance.IsCurrentInstance)
            {
                // If we successfully registered this instance, we can now just
                // go ahead and do normal XAML initialization.
                global::Windows.UI.Xaml.Application.Start((p) => new App());
            }
            else
            {
                // Some other instance has registered for this key, so we'll 
                // redirect this activation to that instance instead.
                instance.RedirectActivationTo();
            }
        }
    }
}