如何从 WinForms 中的子任务更新 UI [英] How to update UI from child tasks in WinForms

问题描述

我有一个简单的小型 winforms 应用程序，它通过 TPL 任务在另一个线程上执行长时间运行的进程.在这个长期运行的过程中，我想更新 UI(进度条或其他东西).有没有办法在不需要 .ContinueWith() 的情况下做到这一点?

I've got a simple little winforms app that performs a long running process on another thread via a TPL Task. During this long running process I'd like to update the UI (the progress bar or something). Is there a way to do this without being required to .ContinueWith()?

public partial class Form1 : Form
{
    private Task _childTask;

    public Form1()
    {
        InitializeComponent();

        Task.Factory.StartNew(() =>
        {
            // Do some work
            Thread.Sleep(1000);

            // Update the UI
            _childTask.Start();

            // Do more work
            Thread.Sleep(1000);
        });

        _childTask = new Task((antecedent) =>
        {
            Thread.Sleep(2000);
            textBox1.Text = "From child task";
        }, TaskScheduler.FromCurrentSynchronizationContext());


    }
}

执行此代码我得到无处不在的异常:

Executing this code I get the ubiquitous exception:

跨线程操作无效:控件textBox1"是从创建它的线程以外的线程访问的.

Cross-thread operation not valid: Control 'textBox1' accessed from a thread other than the thread it was created on.

推荐答案

是的，您可以显式调用 BeginInvoke 在要与之通信的窗口/控件上.在您的情况下，这看起来像这样:

Yes, you can explicitly call BeginInvoke on the Window/Control that you want to communicate with. In your case this would look like this:

this.textBox.BeginInvoke(new Action(() =>
{
   this.textBox.Text = "From child task.";
}));

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