TextBox的Validation.ErrorTemplate对齐TextBox

要对齐Validation.ErrorTemplate和TextBox，可以使用Grid和SharedSizeGroup。例如：

<Grid>
    <Grid.Resources>
        <Style TargetType="{x:Type TextBox}">
            <Setter Property="Margin" Value="5"/>
            <Setter Property="Height" Value="30"/>
            <Setter Property="HorizontalAlignment" Value="Stretch"/>
            <Setter Property="VerticalAlignment" Value="Center"/>
        </Style>
        <Style x:Key="ErrorTemplate" TargetType="{x:Type Control}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate>
                        <StackPanel Orientation="Horizontal" Grid.IsSharedSizeScope="True">
                            <Image Source="error.png" Width="16" Height="16" Margin="0,0,5,0"/>
                            <TextBlock Text="{Binding}" Foreground="Red" Margin="0,0,5,0" VerticalAlignment="Center"/>
                        </StackPanel>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Grid.Resources>

    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" SharedSizeGroup="Label"/>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>

    <TextBlock Text="Name:" Grid.Column="0" VerticalAlignment="Center"/>
    <TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" Grid.Column="1">
        <Validation.ErrorTemplate>
            <ControlTemplate>
                <Border BorderBrush="Red" BorderThickness="1">
                    <AdornedElementPlaceholder/>
                </Border>
            </ControlTemplate>
        </Validation.ErrorTemplate>
    </TextBox>

    <TextBlock Text="Age:" Grid.Column="0" VerticalAlignment="Center"/>
    <TextBox Text="{Binding Age, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" Grid.Column="1">
        <Validation.ErrorTemplate>
            <ControlTemplate>
                <Border BorderBrush="Red" BorderThickness="1">
                    <AdornedElementPlaceholder>
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto" SharedSizeGroup="Label"/>
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <Border BorderBrush="Red" BorderThickness="1" Grid.Column="1">
                                <StackPanel Orientation="Horizontal">
                                    <Image Source="error.png" Width="16" Height="16" Margin="0,0,5,0"/>
                                    <TextBlock Text="{Binding}" Foreground="Red" Margin="0,0,5,0" VerticalAlignment="Center"/>
                                </StackPanel>
                            </Border>
                        </Grid>
                    </AdornedElementPlaceholder>
                </Border>
            </ControlTemplate>
        </Validation.ErrorTemplate>
    </TextBox>
</Grid>

在上面的示例中，我们将TextBox和ErrorTemplate放在一个Grid中，并使用SharedSizeGroup将它们对齐。我们还为TextBox和ErrorTemplate创建了两个Style，以便可以重用它们。对于ErrorTemplate，我们使用了一个StackPanel来放置错误图像和文本，然后将它们放在一个Grid中，这样它们就可以与TextBox对齐。