C＃WPF使用另一个窗口上的按钮控制标签不透明度

Question

I got a small program which uses 2 transparent windows. To position them i added a small colored label. I got this on both transparent windows. Transparent window1 has 2 buttons increase and decrease opacity. This button works for transparent window1 but not for transparent windows2.

 private void BtnIncreaseOpacity_Click(object sender, RoutedEventArgs e)
{
lblDrag.Opacity = 100;
win2.lblDrag2.Opacity = 100;
}

In the Public partial class

TrackerMessage win2 = new TrackerMessage();

The code is accepted, but it does not work. So i am pretty sure this is doing something different then i think.

The other problem is similar. the transparent windows2(win2) needs to make its labels visible when a timer on transparent window1 reaches 0. But thats more of the same problem, since right now you cannot access anything from window1 on window2

So the question is, what am i doing wrong.

Answer 1

Really, both Opacity properties should be bound to a view model and then the button's command modifies the backing properties (allowing the UI to update).

That said, at the very least you should have each window handling its own UI (and I suspect that is the problem). Instead of setting the property directly for win2, have it call a function:

win2.SetOpacity(100);

Where SetOpacity looks like:

public void SetOpacity(int newValue)
{
   lblDrag2.Opacity = newValue;
}

You may also need to do a Dispatcher.BeginInvoke (since this is being called from the other window's UI thread). In that case, the function is:

public void SetOpacity(int newValue)
{
   Dispatcher.BeginInvoke(new Action(() =>
   {
      lblDrag2.Opacity = newValue;
   }));
}

Let me know if I can clarify anything!