WPF显示TextBlock,并在控件下面显示验证错误消息

Question

有没有办法在控件下面的TextBlock中显示错误内容,类似于下面如何设置Tooltip包含错误文本？

        <Style x:Key="textBoxInError" TargetType="Control">
        <Setter Property="Validation.ErrorTemplate">
            <Setter.Value>
                <ControlTemplate>
                    <DockPanel>
                        <TextBlock DockPanel.Dock="Left" Foreground="Red" FontWeight="Bold">*</TextBlock>
                        <TextBlock Text="WOULD LIKE TO SHOW WHAT TOOLTIP IS SHOWING" DockPanel.Dock="Bottom" Foreground="Red"/>
                        <Border BorderBrush="Red" BorderThickness="2">
                            <AdornedElementPlaceholder/>
                        </Border>
                    </DockPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Setter Property="ToolTip"
                        Value="{Binding RelativeSource={x:Static RelativeSource.Self},
                    Path=(Validation.Errors)[0].ErrorContent}"/>
            </Trigger>
        </Style.Triggers>
    </Style>

换句话说,我宁愿在控件下面的TextBlock中显示错误消息,而不是工具提示.

Answer 1

ErrorTemplate的DataContext已经是Validation.Errors的值,所以你可以这样做:

<TextBlock Text="{Binding [0].ErrorContent}" DockPanel.Dock="Bottom" Foreground="Red"/>

要么

<TextBlock Text="{Binding ErrorContent}" DockPanel.Dock="Bottom" Foreground="Red"/>