Question

我有一个文本框：

<TextBox Grid.Row="3"
         Grid.Column="1"
         Width="200"
         TextWrapping="Wrap"
         VerticalAlignment="Top"
         Margin="5,10,-10,2"
         Style="{StaticResource TextBoxValueStyle}"
         Validation.ErrorTemplate="{StaticResource ValidationControlTemplate}">                        
                    <TextBox.Text>
                        <MultiBinding StringFormat=" {0} {1}">
                            <Binding Path="Id" ValidatesOnNotifyDataErrors="True" NotifyOnValidationError="True"/>
                            <Binding Path="Name"  />
                        </MultiBinding>
                    </TextBox.Text>
</TextBox>

这是我的控制模板：

<ControlTemplate x:Key="ValidationControlTemplate">
    <DockPanel Visibility="{Binding ElementName=Placeholder, Path=Visibility}">

        <Image x:Name="Image"
               DockPanel.Dock="Right"
               VerticalAlignment="Center"
               Margin="0,-2"
               Style="{StaticResource InformationImageStyle}">
            <Image.ToolTip>
                <ItemsControl ItemsSource="{Binding}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding ErrorContent}"/>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </Image.ToolTip>

        </Image>
        <AdornedElementPlaceholder Name="Placeholder" VerticalAlignment="Center"/>
    </DockPanel>
    <ControlTemplate.Triggers>
        <Trigger Property="TextBox.Text" Value="">
            <Setter Property="DockPanel.Dock" TargetName="Image" Value="Left"/>
            <Setter Property="Margin" TargetName="Image" Value="-20,-2"/>
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

我的问题是，当文本框具有值（并且有错误）时，它没有采用原始值（DockPanel.Dock = Right and Margin = 0，-2）

我总是以空文本开头。出现错误时，图像始终显示在左侧。

我想念什么？

Answer 1

在Grid元素周围放置<AdornedElementPlaceholder />，并用绑定到装饰的Trigger元素的DataTrigger替换TextBox：

<ControlTemplate x:Key="ValidationControlTemplate">
    <DockPanel Visibility="{Binding ElementName=Placeholder, Path=Visibility}">
        <Image x:Name="Image"
                       DockPanel.Dock="Right"
                       VerticalAlignment="Center"
                       Margin="0,-2"
                       Style="{StaticResource InformationImageStyle}">
            <Image.ToolTip>
                <ItemsControl ItemsSource="{Binding}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <TextBlock Text="{Binding ErrorContent}"/>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </Image.ToolTip>
        </Image>
        <Grid>
            <AdornedElementPlaceholder Name="Placeholder" VerticalAlignment="Center"/>
        </Grid>
    </DockPanel>
    <ControlTemplate.Triggers>
        <DataTrigger Binding="{Binding AdornedElement.Text.Length, ElementName=Placeholder}" Value="0">
            <Setter Property="DockPanel.Dock" TargetName="Image" Value="Left"/>
            <Setter Property="Margin" TargetName="Image" Value="-20,-2"/>
        </DataTrigger>
    </ControlTemplate.Triggers>
</ControlTemplate>

WPF文本框验证ControlTemplate在文本值上触发

1 个答案: