Question

当我在WPF应用程序中使用Task.Run运行进程时，我遇到了触发Process.Exited事件的问题。如果由于进程类限制而导致此Exited事件超出问题，我想在任务完成时更新TextBox.Text。我没有运气也尝试过ContinueWith

async private void Select_Click(object sender, RoutedEventArgs e)
    {
        CancellationToken ct = new CancellationToken();
        CancellationTokenSource cts = new CancellationTokenSource();

        FolderBrowserDialog diag;
        TaskCompletionSource<object> tcs = new TaskCompletionSource<object>();
        Notification.Text = string.Empty;
        diag = new FolderBrowserDialog();
        var result = diag.ShowDialog();
        var istest = TestMode.IsChecked == true;

        if (result == System.Windows.Forms.DialogResult.OK)
        {
            var path = diag.SelectedPath;
            await Task.Run(() =>
            {
                var processStartInfo = new ProcessStartInfo()
                                {
                                    FileName = "cmd.exe",
                                    WindowStyle = ProcessWindowStyle.Hidden,
                                    RedirectStandardOutput = true,
                                    RedirectStandardError = true,
                                    RedirectStandardInput = true,
                                    UseShellExecute = false,
                                    CreateNoWindow = true
                                };
                var command="ping yahoo.com";

                var process = new Process() { StartInfo = processStartInfo, EnableRaisingEvents = true };
                process.Start();

                process.BeginOutputReadLine();
                process.BeginErrorReadLine();
                process.StandardInput.WriteLineAsync(command);
                process.ErrorDataReceived += (p, @event) =>
                {
                    Dispatcher.InvokeAsync(() =>
                    {
                        Notification.AppendText(String.Format("Error {0} {1}", @event.Data, Environment.NewLine));
                    }, System.Windows.Threading.DispatcherPriority.Background);
                };
                process.OutputDataReceived += (p, @event) =>
                {
                    Dispatcher.InvokeAsync(() =>
                    {
                        Notification.AppendText(@event.Data + Environment.NewLine);
                    }, System.Windows.Threading.DispatcherPriority.Background);
                };
                process.WaitForExit();
                process.Exited += (@Sender, args) =>
                {
                    tcs.SetResult(process);
                    System.Windows.MessageBox.Show("Done");
                    process.Dispose();
                };
            });

        }

    }

所有其他事件都没有任何问题被解雇。谢谢

Answer 1

在订阅WaitForExit事件之前调用Exited，因此线程将在那里等待，直到进程退出，并且在进程退出之前从不订阅事件。当WaitForExit返回进程已经退出时，只有您订阅了永远不会再触发的Exited事件。

因此，在致电Exited之前订阅WaitForExit个事件。

process.Exited += (@Sender, args) =>
{
    tcs.SetResult(process);
    System.Windows.MessageBox.Show("Done");
    process.Dispose();
};
process.WaitForExit();

在Task.Run中运行时未达到Process.Exited

1 个答案: