如何启动UWP应用并隐藏窗口，实现WPF调用无线投屏功能？

1. 采用WinUI 3嵌入WPF（XAML Islands），避免独立UWP进程 #

直接在WPF项目中嵌入WinUI控件，在同一个进程内调用WinRT的ProjectionManager API，无需单独启动UWP进程，自然解决窗口隐藏问题。

实现步骤： #

• 在WPF项目中添加Microsoft.Toolkit.Wpf.UI.XamlHost和Microsoft.UI.Xaml NuGet包。
• 在WPF窗口的XAML中添加WindowsXamlHost控件，承载WinUI环境：

  <xamlHost:WindowsXamlHost InitialTypeName="Microsoft.UI.Xaml.Controls.Grid" x:Name="WinUIHost"/>
  

• 在后台代码中获取WinUI对应的CoreWindow和ApplicationView，调用投屏API后隐藏WinUI窗口：

  using Windows.UI.ViewManagement;
  using Windows.Media.Casting;
  using Microsoft.Toolkit.Wpf.UI.XamlHost;
  
  private async void StartProjection_Click(object sender, RoutedEventArgs e)
  {
      // 获取WinUI对应的CoreWindow实例
      var coreWindow = WinUIHost.WindowHandle.GetCoreWindow();
      if (coreWindow == null) return;
  
      // 获取当前WinUI环境的ApplicationView
      var appView = ApplicationView.GetForCurrentView();
  
      // 隐藏WinUI窗口（无需显示给用户）
      coreWindow.Visibility = Windows.UI.Core.CoreWindowVisibility.Collapsed;
  
      // 选择投屏设备并启动投射
      var picker = new CastDevicePicker();
      var selectedDevice = await picker.PickDeviceAsync();
      if (selectedDevice != null)
      {
          // 传入当前ApplicationView的ID作为源和目标视图ID
          await ProjectionManager.StartProjectingAsync(appView.Id, appView.Id);
      }
  }
  

2. 独立UWP进程+IPC通信，启动时隐藏UWP窗口 #

若必须保留独立UWP进程，可让UWP启动时自动隐藏窗口，通过进程间通信（IPC）接收WPF的投屏指令。

UWP端实现： #

• 在App.xaml.cs的OnLaunched方法中直接隐藏主窗口：

  protected override async void OnLaunched(LaunchActivatedEventArgs e)
  {
      // 不显示UWP主窗口
      Window.Current.Hide();
  
      // 注册App Service，接收WPF的投屏请求
      var appServiceConnection = new AppServiceConnection();
      appServiceConnection.AppServiceName = "com.wpf.projection.service";
      appServiceConnection.PackageFamilyName = Windows.ApplicationModel.Package.Current.Id.FamilyName;
      appServiceConnection.RequestReceived += OnProjectionRequestReceived;
  
      await appServiceConnection.OpenAsync();
  }
  
  private async void OnProjectionRequestReceived(AppServiceConnection sender, AppServiceRequestReceivedEventArgs args)
  {
      var requestData = args.Request.Message;
      if (requestData.ContainsKey("StartProjection"))
      {
          var appView = ApplicationView.GetForCurrentView();
          // 启动投屏
          await ProjectionManager.StartProjectingAsync(appView.Id, appView.Id);
          // 回复WPF请求结果
          await args.Request.SendResponseAsync(new Windows.Foundation.Collections.ValueSet { { "Status", "Success" } });
      }
  }
  

• 在UWP的Package.appxmanifest中声明App Service扩展：

  <Extensions>
    <uap:Extension Category="windows.appService">
      <uap:AppService Name="com.wpf.projection.service"/>
    </uap:Extension>
  </Extensions>
  

WPF端实现： #

• 通过App Service连接到UWP进程，发送投屏指令：

  using Windows.ApplicationModel.AppService;
  using Windows.Foundation.Collections;
  
  private async void TriggerProjection_Click(object sender, RoutedEventArgs e)
  {
      var connection = new AppServiceConnection();
      connection.AppServiceName = "com.wpf.projection.service";
      // 替换为你的UWP包家族名（可在UWP项目的Package.appxmanifest中查看）
      connection.PackageFamilyName = "YourUwpPackageFamilyName";
  
      var connectionStatus = await connection.OpenAsync();
      if (connectionStatus == AppServiceConnectionStatus.Success)
      {
          var response = await connection.SendMessageAsync(new ValueSet { { "StartProjection", "" } });
          if (response.Status == AppServiceResponseStatus.Success)
          {
              // 投屏指令已发送
          }
      }
  }
  

3. 用Desktop Bridge打包WPF与UWP，优化进程协同 #

将WPF和UWP打包为同一个MSIX包，两者共享权限、资源，UWP可作为后台辅助进程启动，进一步降低用户感知。

关键优势： #

• UWP进程启动时不会在任务栏显示图标（需隐藏主窗口，注意ProjectionManager依赖UI线程，不能用纯后台任务）。
• 进程间通信更稳定，无需额外配置防火墙规则。

通用注意事项： #

• UWP需声明privateNetworkClientServer权限（用于发现投屏设备），若需捕获桌面屏幕，还需添加screenCapture权限。
• ProjectionManager.StartProjectingAsync的两个参数：第一个是要投射的目标视图ID，第二个是源视图ID；若需投射桌面而非UWP内容，需结合ScreenCapture API捕获桌面画面后再投射。

内容的提问来源于stack exchange，提问作者Tom Xue