Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
259 views
in Technique[技术] by (71.8m points)

c# - Default TextBlock style overriding button text color

My problem occurs with WPF in .NET 3.5 SP1 and can be described as follows:

I have a default Style hitting all TextBlock elements in my UI. That is how it looks:

<Style TargetType="{x:Type TextBlock}">
   <Setter Property="TextTrimming" Value="CharacterEllipsis"/>
   <Setter Property="Foreground" Value="Red"/>
</Style>

That works fine for all TextBlocks. In addition to that I have a Button style including a ControlTemplate that looks like this (shortened):

<Style x:Key="MyButtonStyle" TargetType="{x:Type Button}" BasedOn="{x:Null}">
   <Setter Property="Foreground" Value="Green"/>
   <Setter Property="Template">
      <Setter.Value>
         <ControlTemplate TargetType="{x:Type Button}">
            <Border x:Name="Border" 
                    Background="{TemplateBinding Background}" 
                    BorderThickness="{TemplateBinding BorderThickness}" 
                    Padding="{TemplateBinding Padding}" 
                    Height="24" 
                    BorderBrush="{TemplateBinding BorderBrush}">
               <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                 VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                 TextBlock.Foreground="{TemplateBinding Foreground}"/>
            </Border>
            <ControlTemplate.Triggers>...</ControlTemplate.Triggers>
         </ControlTemplate>
      </Setter.Value>
   </Setter>
</Style>

Notice the line TextBlock.Foreground="{TemplateBinding Foreground}" in the ContentPresenter. This should set the button text to green and in fact it does in the designer view of Visual Studio. But when I compile and run the program the button text is red, the text color is set by the default TextBlock style. I verified this with Snoop.

How can I prevent the defaultTextBlock style from overriding the TextBlock.Foreground value? The OverridesDefaultStyle property of ContentPresenter doesn't help in this case.

Any idea?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

See answer 5 at this link

This happends because the ContentPresenter creates a TextBlock for a string content, and since that TextBlock isn't in the visual tree, it will lookup to Application level resource. And if you define a style for the TextBlock at Application level, then it will be applied to these TextBlock within ContentControl

A workaround is to define a DataTemplate for System.String, where we can explicitly use a default TextBlock to display the content. You can place that DataTemplate in the same dictionary you define the TextBlock style so that this DataTemplate will be applied to whatever ContentPresenter effected by your style.

Try adding this to the ResourceDictionary

<DataTemplate DataType="{x:Type sys:String}">
    <TextBlock Text="{Binding}">
        <TextBlock.Resources> 
            <Style TargetType="{x:Type TextBlock}"/>
        </TextBlock.Resources>
    </TextBlock>
</DataTemplate>

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...