wpf control width binding

Question

I have two borders with content, The second border width changes depending on the content, I'm trying to bind the first border to the second border width but it's not working and I'm not sure what i'm missing. Can someone give me some direction please? Below is a example of what I'm currently trying.

<Border x:Name="border1" Width="{Binding Path=Width, ElementName=border2}">
    ... 
</Border>

<Border x:Name="border2">
    ...
</Border>

score 53 · Accepted Answer · edited Jul 21 '21 at 02:37

53

Change the path to ActualWidth.

<Border x:Name="border1" Width="{Binding Path=ActualWidth, ElementName=border2}">
</Border>
<Border x:Name="border2">
</Border>

edited Jul 21 '21 at 02:37

Toni

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answered May 03 '11 at 17:03

H.B.

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Thanks. I looked up ActualWidth and found this link. http://stackoverflow.com/q/607827/684042 it makes sense to me now. thanks. – Terco May 03 '11 at 17:18

FatemehEbrahimiNik · Answer 2 · 2016-08-14T09:09:06.583

4

change path to ViewportWidth too !

<Grid x:Name="mainGrid">
//and some elements exist there
  <Grid> 
    <Border x:Name="border_btn" Width="{Binding ElementName=root ,Path=ViewportWidth, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>  
  </Grid>
</Grid>

use ViewportWidth instead of ActualWidth because in this case ActualWidth is always shown 0! for test this problem you can test this with this line in your xaml.

  <TextBlock Text="{Binding  ElementName=mainGrid, Path=ActualWidth ,Mode=TwoWay}" Foreground="Red"/>

edited Aug 14 '16 at 09:09

answered Aug 14 '16 at 07:56

FatemehEbrahimiNik

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@Bart its an answer not a comment! – FatemehEbrahimiNik Aug 14 '16 at 08:21
There's already an accepted answer on a 5 year old question, if you think your answer is better, it should be more descriptive than 5 words and explain why yours is better. – Bart Aug 14 '16 at 08:23

wpf control width binding

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