Question

有人能解释为什么CornerRadius的TextBox资源样式很好用，但是BorderThickness和BorderBrush的作用为零吗？

<TextBox Text="TextBox with CornerRadius but no thickness and color" 
         HorizontalContentAlignment="Center"
         VerticalContentAlignment="Center"
         VerticalAlignment="Center" Width="500" Height="100">
    <TextBox.Resources>
        <Style TargetType="{x:Type Border}">                
            <Setter Property="CornerRadius" Value="30" />
            <Setter Property="BorderThickness" Value="30" />
            <Setter Property="BorderBrush" Value="Red" />
        </Style>
    </TextBox.Resources>
</TextBox>

Answer 1

TextBox模板中Border元素的BorderThickness和BorderBrush绑定到模板控件的尊重属性，即TextBox：

<ControlTemplate TargetType="TextBox">
    <Border BorderBrush="{TemplateBinding BorderBrush}"
            BorderThickness="{TemplateBinding BorderThickness}" ...>
        ...            
    </Border>
</ControlTemplate>

这些绑定会覆盖任何“边框样式设置器”中的值。

您应该以文本框样式设置值：

<TextBox Text="TextBox with CornerRadius but no thickness and color" 
        HorizontalContentAlignment="Center"
        VerticalContentAlignment="Center"
        VerticalAlignment="Center" Width="500" Height="100">
    <TextBox.Style>
        <Style TargetType="TextBox">
            <Style.Resources>
                <Style TargetType="Border">
                    <Setter Property="CornerRadius" Value="30"/>
                </Style>
            </Style.Resources>
            <Setter Property="BorderThickness" Value="30"/>
            <Setter Property="BorderBrush" Value="Red"/>
        </Style>
    </TextBox.Style>
</TextBox>

Answer 2

原因是在标准TextBoxBase的模板中，边框控件的属性BorderThickness和BorderBrush绑定到与TextBox本身相同的属性。 / p>

以下是样式中使用的标准ControlTemplate：

<ControlTemplate TargetType="{x:Type TextBoxBase}">
    <cbd:ClassicBorderDecorator x:Name="Bd" BorderStyle="Sunken" Background="{TemplateBinding Control.Background}" BorderThickness="{TemplateBinding Control.BorderThickness}" BorderBrush="{TemplateBinding Control.BorderBrush}">
        <ScrollViewer Name="PART_ContentHost" />
    </cbd:ClassicBorderDecorator>
    <ControlTemplate.Triggers>
        <Trigger Property="UIElement.IsEnabled" Value="False">
            <Setter TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" Property="theme:ClassicBorderDecorator.Background" />
            <Setter Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" Property="Control.Foreground" />
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

要达到目标，可以通过以下方式设置这些属性：

<TextBox Text="TextBox with CornerRadius but no thickness and color" 
        HorizontalContentAlignment="Center" BorderThickness="30" BorderBrush="Red"
        VerticalContentAlignment="Center"
        VerticalAlignment="Center" Width="500" Height="100">
        <TextBox.Resources>
        <Style TargetType="{x:Type Border}">
            <Setter Property="CornerRadius" Value="30" />
        </Style>
    </TextBox.Resources>
</TextBox>

希望它能对您有所帮助。

WPF文本框样式问题

2 个答案: