通过代码刷新WPF控制 [英] Refresh WPF-Control by code

问题描述

我正试图禁用一个拒绝垃圾邮件按钮的按钮。

I am trying to disable a button for denying a spam click on this button.

我使用了Refresh委托来渲染控件，但该控件显示为已启用。
connect（）-Methode在巫婆中花费了大约4秒钟，按钮显示为已启用。

I used a Refresh delegate to Render invoke the control but it appears as enabled. The connect()-Methode is taking about 4 seconds in witch the button is shown as enabled.

问题出在哪里？

public static class ExtensionMethods
{

   private static Action EmptyDelegate = delegate() { };


   public static void Refresh(this UIElement uiElement)
   {
      uiElement.Dispatcher.Invoke(DispatcherPriority.Render, EmptyDelegate);
   }
}


private void buttonConnect_Click(object sender, RoutedEventArgs e)
{
    this.Cursor = Cursors.Wait;
    buttonConnect.IsEnabled = false;
    buttonConnect.Refresh();

    if (buttonConnect.Content.Equals("Connect"))
    {
        connect();
    }
    else
    {
        disconnect();
    }
    buttonConnect.IsEnabled = true;
    buttonConnect.Refresh();
    this.Cursor = Cursors.Arrow;
}

推荐答案

在UI线程上，UI没有时间在其间进行更新，您需要在后台线程上运行任务，并在完成后再次更改UI（例如，使用 BackgroundWorker 已具有 RunWorkerCompleted 事件）。

Since all that appears to happen on the UI-Thread the UI has no time to update in-between, you need to run your task on a background thread and change the UI again on completion (e.g. use a BackgroundWorker which already has a RunWorkerCompleted event).

例如

button.IsEnabled = false;
var bw = new BackgroundWorker();
bw.DoWork += (s, _) =>
{
    //Long-running things.
};
bw.RunWorkerCompleted += (s,_) => button.IsEnabled = true;
bw.RunWorkerAsync();

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