Poor Performance When Dynamically Resizing a WPF TextBlock

Answer 1

I apologize if you've tried this, but does setting TextBlock.TextWrapping to "Wrap" not accomplish your goal?

I'm guessing that will get rid of the need for the bind-to-width stuff you're doing, as the Grid will take care of the resizing. (That is probably what is happening now: The Grid is laying out the controls as it shrinks, and the binding to width is changing the size slightly, causing the dancing.)

[Update]

I tried to duplicate the behavior you're seeing, but it works fine for me. I made a simple style for the TextBlocks like so:

<Style x:Key="DetailText" TargetType="{x:Type TextBlock}">
    <Setter Property="TextBlock.TextWrapping" Value="Wrap"/>                
</Style>

And I didn't have any of your other dynamic resources (DetailHeadingBorder, DetailHeadingText, or ColumnBorderBrush), so everything was black and white (fine).

Maybe you just have a really old graphics card and it's rendering things in software? Or it has to do with your styles.

Answer 2

I hope I didn't misinterpret your question, but I don't see the need for binding TextBlock.Width?

This xaml seems to work correctly:

  <Grid>
     <Grid.ColumnDefinitions>
        <ColumnDefinition MinWidth="270"
                          Width="2*" />
        <ColumnDefinition MinWidth="160"
                          Width="*" />
        <ColumnDefinition MinWidth="160"
                          Width="*" />
        <ColumnDefinition MinWidth="160"
                          Width="*" />
     </Grid.ColumnDefinitions>
     <!--     We bind the width of the textblock to the width of this border to make sure things resize correctly.    
     It's important that the margin be set to 1 larger than the margin of the textblock or else you'll end  
       up in an infinate loop     -->
     <Border Grid.Column="0"
             BorderThickness="0,0,1,0">
        <Grid>
           <Grid.RowDefinitions>
              <RowDefinition Height="*" />
              <RowDefinition Height="*" />
           </Grid.RowDefinitions>
           <StackPanel Grid.Row="0">
              <Border>
                 <TextBlock Text="Col 1 Row 1" />
              </Border>
              <TextBlock TextWrapping="Wrap"
                         Text="gfege dfh lh dfl dhliöslghklj h lglsdg fklghglfg flg lgheh" />
           </StackPanel>
           <StackPanel Grid.Row="1">
              <Border>
                 <TextBlock Text="Col 1 Row 2" />
              </Border>
              <TextBlock Text="Massor av text som blir en wrappning i slutändan hoppas jag"
                         TextWrapping="Wrap" />
           </StackPanel>
        </Grid>
     </Border>
  </Grid>

I just removed the width bindings, added TextWrapping (which you probably had in a style), and removed the border named "FirstBorder" as well.

Answer 3

I hate to answer my own question, but it appears that I may have found out what I was doing incorrectly. Since it's been so long since the original question was asked, I cannot remember every step I attempted to take, but this is what I do know. The style on each textblock was set as such:

<Style x:Key="DetailText" TargetType="TextBlock">
    <Setter Property="HorizontalAlignment" Value="Center" /> 
    <Setter Property="TextWrapping" Value="Wrap" /> 
    <Setter Property="TextAlignment" Value="Center" />
    <Setter Property="Margin" Value="5,5,5,5" />
</Style>

At that time, I'm assuming that did not produce the desired results and therefore I had to bind the width of the textblock to that of the column. In playing around today, I changed the style to the following (note the different HorizontalAlignment) and removed the bindings and found out that my problem had been resolved:

<Style x:Key="DetailText" TargetType="TextBlock">
    <Setter Property="HorizontalAlignment" Value="Stretch" />
    <Setter Property="TextWrapping" Value="Wrap" />
    <Setter Property="TextAlignment" Value="Center" />
    <Setter Property="Margin" Value="5,5,5,5" />
</Style>