process.WaitForExit（）異步

Question

我想等待一個進程完成，但process.WaitForExit()掛起我的GUI。有沒有基於事件的方式，還是我需要產生一個線程阻塞直到退出，然後自己委託事件？

Answer 1

process.EnableRaisingEvents = true;
process.Exited + = [EventHandler]

Answer 2

使用System.Diagnostics.Process.Exited

Answer 3

According to this link的WaitForExit（）方法用於使當前線程等待，直到關聯的過程終止。但是，流程確實有一個您可以掛鉤的Exited事件。

Answer 4

從.NET 4.0/C＃5開始，使用異步模式來表示它會更好。

/// <summary> 
/// Waits asynchronously for the process to exit. 
/// </summary> 
/// <param name="process">The process to wait for cancellation.</param> 
/// <param name="cancellationToken">A cancellation token. If invoked, the task will return 
/// immediately as canceled.</param> 
/// <returns>A Task representing waiting for the process to end.</returns> 
public static Task WaitForExitAsync(this Process process, 
    CancellationToken cancellationToken = default(CancellationToken)) 
{ 
    var tcs = new TaskCompletionSource<object>(); 
    process.EnableRaisingEvents = true; 
    process.Exited += (sender, args) => tcs.TrySetResult(null); 
    if(cancellationToken != default(CancellationToken)) 
     cancellationToken.Register(tcs.SetCanceled); 

    return tcs.Task; 
} 

用法：

public async void Test() 
{ 
    var process = new Process("processName"); 
    process.Start(); 
    await process.WaitForExitAsync(); 

    //Do some fun stuff here... 
} 

Answer 5

如果選擇@MgSam答案，要知道，如果你通過WaitForExitAsync一些CancellationToken，將在指定延遲後自動取消，你可以得到一個InvalidOperationException。爲了解決這個問題，你需要改變

cancellationToken.Register(tcs.SetCanceled); 

到

cancellationToken.Register(() => { tcs.TrySetCanceled(); }); 

P.S：不要忘記處置您CancellationTokenSource的時間。