Question

我是.Net Threads的新手。我知道我们不能在主线程中使用WinForm GUI。我想要一个更新WinForm GUI的方法，在第二个线程结束后立即在主线程中运行。这是我的代码的一部分：

public class FormGApp : Form
{
    private Thread m_LoginThread;

    private void buttonLogin_Click(object sender, EventArgs e)
    {
        m_LoginThread = new Thread(new ThreadStart(this.login));                   
        m_LoginThread.Start();                 
    }

    private void login()
    {
        LoginResult result = loginToServer();
        this.User = result.LoggedInUser;
    }

    private void successfullyLogin()
    {
        // Update the WinForn GUI here...
        // This method must run in the main thread!!!
    }
}

如何在successfullyLogin()结束时运行方法m_LoginThread？

Answer 1

您有几个选择：

正如@ScottChamberlain在评论中所说，使用BackgroundWorker并使用其Completed事件来更新GUI

以下列方式使用TPL Library：

Task.Run(() => 
  {
    //do work
  }).ContinueWith(() => 
      {
          //do continuation
      }, TaskScheduler.FromCurrentSynchronizationContext);

使用后台主题中的Application.Current.BeginInvoke或Application.Current.Invoke

Answer 2

如果您使用的是.Net 4.5，则可以使用async / await

async private void buttonLogin_Click(object sender, EventArgs e)
{
    await Task.Run(() => login());
    successfullyLogin();
}

Answer 3

感谢大家鼓励我使用BackgroundWorker，它确实解决了这个问题。这是我的解决方案：

public partial class FormGApp : Form
{
    private BackgroundWorker m_LoginBackgroundWorker;

    // ctor:
    public FormGApp()
    {
         // init thread:
         this.m_LoginBackgroundWorker = new BackgroundWorker();
         this.m_LoginBackgroundWorker.DoWork += this.LoginBackgroundWorker_DoWork;
         this.m_LoginBackgroundWorker.RunWorkerCompleted += this.LoginBackgroundWorker_RunWorkerCompleted;
    }

    private void buttonLogin_Click(object sender, EventArgs e)
    {
         // start thread:
         this.m_LoginBackgroundWorker.RunWorkerAsync();
    }

    private void LoginBackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
    {
         this.login();
    }

    private void LoginBackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
         this.successfullyLogin();
    }

    private void login()
    {
         // code that take long time that executed in a separate thread... 
    }

    private void successfullyLogin()
    {
         // Gui WinForm update code here...
    }

如何在子线程结束后在主线程中运行一个方法？

3 个答案: