更新WPF在运行时控制 [英] Update WPF controls at run time

问题描述

我试着写一个WPF应用程序，它会在运行时使用线程更新一组文本框和标签，但问题是，当过一个线程试图更新文本框和标签，我得到了以下错误： 调用线程不能访问此对象，因为不同的线程拥有它。是否有可能更新在运行时的控制？

I'm trying to write a WPF application that will update a set of text boxes and labels at run time using threads but the problem is that when ever a thread tries to update the text boxes and labels I get the following error: "The calling thread cannot access this object because a different thread owns it." Is it possible to update the control at run time?

推荐答案

是的，但你必须使用更新的 Dispatcher.Invoke 。

Yes, but you have to update the UI elements in the UI thread using Dispatcher.Invoke.

实例在C＃中：而不是

myTextBox.Text = myText;

使用

Dispatcher.Invoke(new Action(() => myTextBox.Text = myText));

VB.NET（前4版）不支持匿名方法，所以你必须用一个匿名函数解决方法是：

VB.NET (before version 4) does not support anonymous methods, so you'll have to workaround it with an anonymous function:

Dispatcher.Invoke(Function() UpdateMyTextBox(myText))

...

Function UpdateMyTextBox(ByVal text As String) As Object
    myTextBox.Text = text
    Return Nothing
End Function

---

另外，您也可以使用启动后台线程 BackgroundWorker的类，它通过 ProgressChanged 和 RunWorkerCompleted 事件支持在用户界面的更新：这两个事件都引发了UI自动线程。使用BackgroundWorker的一个例子可以在这里找到：<一href="http://stackoverflow.com/questions/1754827/wpf-update-ui-from-viewmodel-class-mvvm-pattern/1754848#1754848">SO问题1754827 。

---

Alternatively, you can start your background threads using the BackgroundWorker class, which support updates in the UI through the ProgressChanged and RunWorkerCompleted events: Both events are raised in the UI thread automatically. An example for using BackgroundWorker can be found here: SO question 1754827.

这篇关于更新WPF在运行时控制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！