如何从UWP应用中关闭FullTrustProcess进程？

问题场景 #

关闭UWP应用时会启动FullTrustProcess（系统托盘进程），托盘右键打开UWP时会自动关闭自身；但双击桌面UWP图标重新启动时，原FullTrustProcess仍在后台运行，导致两者同时存在。需要实现互斥逻辑，确保同一时间仅UWP或FullTrustProcess中的一方处于运行状态。

现有核心代码：

UWP关闭触发FullTrustProcess启动（MainPage.xaml.cs） #

private async void HandleSystemNavigationManagerCloseRequested(object sender, SystemNavigationCloseRequestedPreviewEventArgs e)
{
    if (ApiInformation.IsApiContractPresent("Windows.ApplicationModel.FullTrustAppContract", 1, 0))
    {
        await FullTrustProcessLauncher.LaunchFullTrustProcessForCurrentAppAsync();
    }
}

托盘进程唤起UWP并自关闭 #

private async void OpenUWPApp(object sender, EventArgs e)
{
    var appListEntries = await Package.Current.GetAppListEntriesAsync();
    await appListEntries.First().LaunchAsync();
    Application.Exit();
}

UWP的AppService连接逻辑（App.xaml.cs） #

public static AppServiceConnection Connection = null;

protected override void OnBackgroundActivated(BackgroundActivatedEventArgs args)
{
    base.OnBackgroundActivated(args);
    
    if (args.TaskInstance.TriggerDetails is AppServiceTriggerDetails details)
    {
        AppServiceDeferral = args.TaskInstance.GetDeferral();
        args.TaskInstance.Canceled += OnTaskCanceled;
        Connection = details.AppServiceConnection;
        Connection.RequestReceived += HandleSystemTrayConnectionRequestReceived;
        Connection.ServiceClosed += HandleSystemTrayConnectionServiceClosed;
    }
}

曾尝试通过AppServiceConnection通讯，但新UWP会话启动时Connection为null，无法直接发送关闭指令。

解决方案 #

方案1：通过进程名检测并终止FullTrustProcess #

利用P/Invoke调用Win32 API，在UWP启动时检测指定进程并终止：

1. 添加P/Invoke工具类：

using System;
using System.Runtime.InteropServices;
using System.Linq;
using Windows.System;

public static class ProcessHelper
{
    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool TerminateProcess(IntPtr hProcess, uint uExitCode);

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern IntPtr OpenProcess(uint dwDesiredAccess, bool bInheritHandle, uint dwProcessId);

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool CloseHandle(IntPtr hObject);

    private const uint PROCESS_TERMINATE = 0x0001;

    public static async void KillFullTrustProcess(string processName)
    {
        var processes = await ProcessManager.GetProcessesAsync();
        var targetProcess = processes.FirstOrDefault(p => p.ExecutableFileName.Equals(processName, StringComparison.OrdinalIgnoreCase));
        if (targetProcess != null)
        {
            IntPtr hProcess = OpenProcess(PROCESS_TERMINATE, false, (uint)targetProcess.Id);
            if (hProcess != IntPtr.Zero)
            {
                TerminateProcess(hProcess, 0);
                CloseHandle(hProcess);
            }
        }
    }
}

2. 在UWP的OnLaunched事件中调用：

protected override async void OnLaunched(LaunchActivatedEventArgs e)
{
    base.OnLaunched(e);
    // 替换为你的FullTrustProcess可执行文件名，如"YourDesktopTray.exe"
    ProcessHelper.KillFullTrustProcess("YourDesktopTray.exe");
    
    // 其他初始化逻辑
}

方案2：命名管道实现双向通讯 #

在FullTrustProcess中创建命名管道，UWP启动时尝试连接并发送关闭指令：

1. FullTrustProcess侧启动管道服务：

using System.IO.Pipes;
using System.Threading.Tasks;

public class PipeServer
{
    private NamedPipeServerStream _pipeServer;

    public async void Start()
    {
        _pipeServer = new NamedPipeServerStream("UWP_Tray_Pipe", PipeDirection.InOut, 1);
        await _pipeServer.WaitForConnectionAsync();
        
        using (var reader = new StreamReader(_pipeServer))
        {
            string message = await reader.ReadLineAsync();
            if (message == "SHUTDOWN_TRAY")
            {
                Application.Exit();
            }
        }
    }
}

// 托盘进程启动时初始化管道
protected override void OnStartup(StartupEventArgs e)
{
    base.OnStartup(e);
    var pipeServer = new PipeServer();
    pipeServer.Start();
    // 托盘图标初始化等逻辑
}

2. UWP侧发送关闭指令：

using System.IO.Pipes;
using System.Threading.Tasks;

private async Task SendShutdownCommand()
{
    try
    {
        using (var pipeClient = new NamedPipeClientStream(".", "UWP_Tray_Pipe", PipeDirection.InOut))
        {
            await pipeClient.ConnectAsync(1000);
            using (var writer = new StreamWriter(pipeClient))
            {
                await writer.WriteLineAsync("SHUTDOWN_TRAY");
                await writer.FlushAsync();
            }
        }
    }
    catch (TimeoutException)
    {
        // 连接超时，说明托盘进程未运行
    }
}

protected override async void OnLaunched(LaunchActivatedEventArgs e)
{
    base.OnLaunched(e);
    await SendShutdownCommand();
    // 其他初始化逻辑
}

方案3：改进AppService主动连接逻辑 #

让FullTrustProcess启动时主动发起AppService连接，UWP启动时通过新连接发送关闭指令：

1. FullTrustProcess侧主动连接UWP：

using Windows.ApplicationModel.AppService;
using Windows.Foundation.Collections;

private AppServiceConnection _appServiceConnection;

private async Task ConnectToUwp()
{
    _appServiceConnection = new AppServiceConnection();
    _appServiceConnection.AppServiceName = "UWP_Tray_AppService"; // 需与UWP清单中声明一致
    _appServiceConnection.PackageFamilyName = Package.Current.Id.FamilyName;

    var status = await _appServiceConnection.OpenAsync();
    if (status == AppServiceConnectionStatus.Success)
    {
        _appServiceConnection.RequestReceived += (sender, args) =>
        {
            if (args.Request.Message["Command"].ToString() == "SHUTDOWN")
            {
                Application.Exit();
            }
        };
    }
}

// 托盘进程启动时调用
protected override void OnStartup(StartupEventArgs e)
{
    base.OnStartup(e);
    _ = ConnectToUwp();
    // 其他初始化逻辑
}

2. UWP侧发送关闭指令：

private async Task SendShutdownViaAppService()
{
    var appServiceConnection = new AppServiceConnection();
    appServiceConnection.AppServiceName = "UWP_Tray_AppService";
    appServiceConnection.PackageFamilyName = Package.Current.Id.FamilyName;

    var status = await appServiceConnection.OpenAsync();
    if (status == AppServiceConnectionStatus.Success)
    {
        var message = new ValueSet();
        message.Add("Command", "SHUTDOWN");
        await appServiceConnection.SendMessageAsync(message);
        appServiceConnection.Dispose();
    }
}

protected override async void OnLaunched(LaunchActivatedEventArgs e)
{
    base.OnLaunched(e);
    await SendShutdownViaAppService();
    // 其他初始化逻辑
}

参考指南要点 #

原参考的UWP桌面扩展开发核心内容包括：

• UWP与FullTrustProcess的AppService通讯机制
• UWP关闭唤起桌面进程、桌面进程唤起UWP的生命周期协同逻辑
• 进程间通讯的常用方案（AppService、命名管道、共享内存）
• 实现UWP与桌面进程互斥运行的最佳实践

内容的提问来源于stack exchange，提问作者sme