无法从线程C＃启动另一个进程

Question

I'm trying to make an update app for wpf app. I have an "Update" Button and a little round loader. After update button click, loader appears. Update code uses another thread. But when I'm trying to start another process (Process.Start(path)) from update thread, i got an exeption (the calling thread cannot access this object because a different thread owns it).

private void CheckUpdateButton_OnClick(object sender, RoutedEventArgs e)
{
    VisibleLoadingForCheckUpdate = true;
    var myThread = new Thread(CheckNeedUpdateApplication);
    myThread.Start();
    myThread.Name = "UpdateThread";
    IsEnabled = false;
}

private void CheckNeedUpdateApplication()
{
    if (_baseWindow.ProgramWorked)
    {
        return;
    }

    try
    {
        var myDelegate = new Action(LoaderStop);
        if (NeedUpdate())
        {
            MessageBoxResult updateDecision =
                MessageBox.Show(@"Install update?",
                    @"Update", MessageBoxButton.YesNo);
            if (updateDecision == MessageBoxResult.Yes)
                InstallUpdate();
            Dispatcher.Invoke(myDelegate);
        }
        else
        {
            MessageBox.Show(@"No update found", @"Update", MessageBoxButton.OK, MessageBoxImage.Information);
            Dispatcher.Invoke(myDelegate);
        }
    }
    catch (Exception)
    {
        MessageBox.Show(this, @"Connection error",
            @"Error", MessageBoxButton.OK, MessageBoxImage.Error);
        var myDelegate = new Action(LoaderStop);
        Dispatcher.Invoke(myDelegate);
        //throw new Exception("Error");
    }
}

void LoaderStop()
{
    VisibleLoadingForCheckUpdate = false;
    IsEnabled = true;
}

private void InstallUpdate()
{
    try
    {
        var newApp = _updateServiceApiClient.GetProgramArchive(_baseWindow.ProgramIdentity);
        if (newApp.IsSuccess)
        {
            using (var decompress = ZipFile.Read(new MemoryStream(newApp.Result)))
            {
                decompress.ExtractAll(Application.StartupPath + Path.DirectorySeparatorChar + "update", ExtractExistingFileAction.OverwriteSilently);
            }
            try
            {
                var pInfo = new ProcessStartInfo(UpdaterFilePath) {UseShellExecute = false};
                var mProcess = new Process {StartInfo = pInfo};
                mProcess.Start(); //EXCEPTION
                _baseWindow.Close();
                Close();
            }
            catch
            {
                MessageBox.Show(this, @"Update Error.",
                                    @"Error", MessageBoxButton.OK, MessageBoxImage.Error);
                LoggerHelper.ErrorsLogger("Update error.");
            }
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(this, @"Update Error",
            @"Error", MessageBoxButton.OK, MessageBoxImage.Error);
        //throw new Exception("Ошибка при обновлении.");
    }
}

How I can start another app from another thread?

Answer 1

you cannot update UI from another thread, as UI runs on MainThread. You are using MessageBox.Show() that needs to be displayed on UI. And also you cannot retreive UI controls values when on another thread. In this case use a Dispatcher to update the UI and read info from UI controls.