Question

I have a global style that sets all my TextBox styles, but in some cases I want to revert just the Foreground color to the original non-custom-style color. I tried using {TemplateBinding Foreground} inside the specific TextBoxes that I wanted to revert. It didn’t end up being valid XAML and I’m not sure that’s the right way anyhow.

Any ideas? Thanks.

Answer 1

There’s a few ways this could be done. If you look at the Precedence List on the MSDN
then you can see that the Forground set in ways 1-8 will override the Foreground from a default style. The easiest way being just to set the local value in the TextBox.

<TextBox Foreground="Red" />

Another thing that you can do is use the 'BasedOn' property of styles to override the other versions. This does require giving a key value to your default style, but that can then be used to also apply the default like in this example:

    <Style TargetType="{x:Type TextBox}"
           x:Key="myTextBoxStyle">
        <Setter Property="Foreground"
                Value="Red" />
        <Setter Property="FontWeight"
                Value="Bold" />
    </Style>
    <!-- Style applies to all TextBoxes -->
    <Style TargetType="{x:Type TextBox}"
           BasedOn="{StaticResource myTextBoxStyle}" />


<TextBox Text="Hello">
    <TextBox.Style>
        <Style BasedOn="{StaticResource myTextBoxStyle}" TargetType="{x:Type TextBox}">
            <Setter Property="Foreground"
                    Value="Blue" />
        </Style>
    </TextBox.Style>
</TextBox>

Edit:
In the case that the default style is applying a value and you want to revert it to the base value there are a few ways I can think of, off hand, to get this behavior. You can’t, that I know of, bind back to the default theme value in a generic manner.

We can however do some other things. If we need the style to not apply some properties, we can set the style to {x:Null}, thus stopping the default style from applying. Or we can give the element it’s own style that does not inherit from the base style and then re-apply only the setters that we need:

        <TextBox Text="Hello" Style="{x:Null}" />
        <TextBox Text="Hello">
            <TextBox.Style>
                <Style TargetType="{x:Type TextBox}">
                    <Setter Property="FontWeight"
                            Value="Bold" />
                </Style>
            </TextBox.Style>
        </TextBox>

We could modify the default style so that the Foreground will only be set on certain conditions, such as the Tag being a certain value.

    <Style TargetType="{x:Type TextBox}"
           x:Key="myTextBoxStyle">
        <Setter Property="FontWeight"
                Value="Bold" />
        <Style.Triggers>
            <Trigger Property="Tag"
                     Value="ApplyForeground">
                <Setter Property="Foreground"
                        Value="Red" />
            </Trigger>
        </Style.Triggers>
    </Style>

   <TextBox Text="Hello" />
    <TextBox Text="Hello" Tag="ApplyForeground" />