Process.Exited 事件

定义

命名空间:

System.Diagnostics

程序集:

System.Diagnostics.Process.dll

Source:

Process.cs

在进程退出时发生。

public:
 event EventHandler ^ Exited;

public event EventHandler Exited;

member this.Exited : EventHandler 

Public Custom Event Exited As EventHandler 

事件类型

EventHandler

示例

下面的代码示例创建一个打印文件的进程。 当进程退出时，它会引发 Exited 事件， EnableRaisingEvents 因为 属性是在创建进程时设置的。 事件处理程序 Exited 显示进程信息。

using System;
using System.Diagnostics;
using System.Threading.Tasks;

class PrintProcessClass
{
    private Process myProcess;
    private TaskCompletionSource<bool> eventHandled;

    // Print a file with any known extension.
    public async Task PrintDoc(string fileName)
    {
        eventHandled = new TaskCompletionSource<bool>();

        using (myProcess = new Process())
        {
            try
            {
                // Start a process to print a file and raise an event when done.
                myProcess.StartInfo.FileName = fileName;
                myProcess.StartInfo.Verb = "Print";
                myProcess.StartInfo.CreateNoWindow = true;
                myProcess.EnableRaisingEvents = true;
                myProcess.Exited += new EventHandler(myProcess_Exited);
                myProcess.Start();
            }
            catch (Exception ex)
            {
                Console.WriteLine($"An error occurred trying to print \"{fileName}\":\n{ex.Message}");
                return;
            }

            // Wait for Exited event, but not more than 30 seconds.
            await Task.WhenAny(eventHandled.Task,Task.Delay(30000));
        }
    }

    // Handle Exited event and display process information.
    private void myProcess_Exited(object sender, System.EventArgs e)
    {
        Console.WriteLine(
            $"Exit time    : {myProcess.ExitTime}\n" +
            $"Exit code    : {myProcess.ExitCode}\n" +
            $"Elapsed time : {Math.Round((myProcess.ExitTime - myProcess.StartTime).TotalMilliseconds)}");
        eventHandled.TrySetResult(true);
    }

    public static async Task Main(string[] args)
    {
        // Verify that an argument has been entered.
        if (args.Length <= 0)
        {
            Console.WriteLine("Enter a file name.");
            return;
        }

        // Create the process and print the document.
        PrintProcessClass myPrintProcess = new PrintProcessClass();
        await myPrintProcess.PrintDoc(args[0]);
    }
}

Imports System.Diagnostics

Class PrintProcessClass

    Private WithEvents myProcess As Process
    Private eventHandled As TaskCompletionSource(Of Boolean)

    ' Print a file with any known extension.
    Async Function PrintDoc(ByVal fileName As String) As Task

        eventHandled = New TaskCompletionSource(Of Boolean)()
        myProcess = New Process
        Using myProcess
            Try
                ' Start a process to print a file and raise an event when done.
                myProcess.StartInfo.FileName = fileName
                myProcess.StartInfo.Verb = "Print"
                myProcess.StartInfo.CreateNoWindow = True
                myProcess.EnableRaisingEvents = True
                AddHandler myProcess.Exited, New EventHandler(AddressOf myProcess_Exited)
                myProcess.Start()

            Catch ex As Exception
                Console.WriteLine("An error occurred trying to print ""{0}"":" &
                vbCrLf & ex.Message, fileName)
                Return
            End Try

            ' Wait for Exited event, but not more than 30 seconds.
            Await Task.WhenAny(eventHandled.Task, Task.Delay(30000))
        End Using
    End Function

    ' Handle Exited event and display process information.
    Private Sub myProcess_Exited(ByVal sender As Object,
            ByVal e As System.EventArgs)

        Console.WriteLine("Exit time:    {0}" & vbCrLf &
            "Exit code:    {1}" & vbCrLf & "Elapsed time: {2}",
            myProcess.ExitTime, myProcess.ExitCode,
            Math.Round((myProcess.ExitTime - myProcess.StartTime).TotalMilliseconds))
        eventHandled.TrySetResult(True)
    End Sub

    Shared Sub Main(ByVal args As String())

        ' Verify that an argument has been entered.
        If args.Length <= 0 Then
            Console.WriteLine("Enter a file name.")
            Return
        End If

        ' Create the process and print the document.
        Dim myPrintProcess As New PrintProcessClass
        myPrintProcess.PrintDoc(args(0)).Wait()

    End Sub
End Class

注解

事件 Exited 指示关联的进程已退出。 此事件意味着进程终止 (中止) 或已成功关闭。 仅当 属性true的值为 时，EnableRaisingEvents才会发生此事件。

当关联进程退出时，可通过两种方式获得通知：同步和异步。 同步通知意味着调用 WaitForExit 方法以阻止当前线程，直到进程退出。 异步通知使用 Exited 事件，它允许调用线程同时继续执行。 在后一种情况下， EnableRaisingEvents 必须将 设置为 true ，调用应用程序才能接收 Exited 事件。

当操作系统关闭进程时，它会通知所有其他进程，这些进程已注册 Exited 事件的处理程序。 此时，刚退出的进程句柄可用于访问某些属性，例如 ExitTime ， HasExited 操作系统会维护这些属性，直到它完全释放该句柄。

注意

即使已退出进程具有句柄，也无法再次调用 Start 以重新连接到同一进程。 调用 Start 会自动释放关联的进程，并连接到具有相同文件但全新的 Handle的进程。

有关在 Windows 窗体 应用程序中使用 Exited 事件的详细信息，请参阅 SynchronizingObject 属性。