WPF label and textbox width

Question

Hello,

Whenever I change my textbox/label from the code behind, the width doesn't update until my function stops running.

For example:

if label.content="test"

and the width returned was 50,

then I change the content to "test test"

I would still get 50 as width unless I restart this function.

Why doesn't the width change when I change the content?

How can I change the width immediately according to the content?

Thanks.

Answer 1

Can you show the code that you are using to see if the width expands ?

And maybe you should use the label.SizeChanged event to update the value instead.

---

Developing is part of being a developer.

Answer 2

I just had a button to show me this:

MessageBox.Show(labeltext.ActualWidth.ToString());
labeltext.Content = "test test";
MessageBox.Show(labeltext.ActualWidth.ToString());

The width that was returned was the same(original text was different).

Also I use ActualWidth since regular Width gives me NaN..

How can I get the new width?

Answer 3

The width will not change untill another layout pass happens (when the function ends the UI will update).  You will have to force this update if you want it immediately.  You can look into the Measure method (possibly UpdateMeasure or UpdateLayout), or you could run the code on a background thread, and Invoke the Label Content change with a Render Priority.

Answer 4

UpdateLayout did the trick, thanks.