WPF 列表框错误模板 [英] WPF ListBox ErrorTemplate

问题描述

在我的 WPF 应用程序中，我有一个 ListBox 绑定到一组视图模型.这些视图模型通过实现 INotifyDataErrorInfo 来支持验证.我正在尝试在我的 ListBox 中显示具有验证错误的项目的错误模板.

In my WPF application I've a ListBox binding to a collection of view models. Those view models support validation by implement INotifyDataErrorInfo. I’m trying to display an error template for items with validation errors in my ListBox.

通过在 ListBox 的 ItemSource 绑定上设置 NotifyOnValidationError=True，我可以让 ListBox 显示默认错误模板.
看起来像这样:

I’m able to get the ListBox to display the default error template by setting NotifyOnValidationError=True on the ItemSource binding of the ListBox.
Which looks like this:

我的列表框代码:

<ListBox x:Name="ListBoxEvents" ItemsSource="{Binding Events, UpdateSourceTrigger=PropertyChanged, NotifyOnValidationError=True}" 
                 IsSynchronizedWithCurrentItem="True" ItemTemplate="{DynamicResource EventListTemplate}"></ListBox>

我的列表框样式:

<ControlTemplate x:Key="ListBoxValidationError">
    <DockPanel LastChildFill="True">
        <Border Background="Red" Margin="5">
            <AdornedElementPlaceholder />
        </Border>
    </DockPanel>
</ControlTemplate>

<Style TargetType="{x:Type ListBox}">
    <Setter Property="BorderBrush" Value="{StaticResource WindowTitleBrush}" />
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="MinWidth" Value="200" />
    <Setter Property="HorizontalContentAlignment" Value="Stretch"></Setter>
    <Setter Property="ScrollViewer.CanContentScroll" Value="False"></Setter>
    <Setter Property="Validation.ErrorTemplate" Value="{StaticResource ListBoxValidationError}"></Setter>
</Style>

ListBox 项模板:

The ListBox item template:

<DataTemplate x:Key="EventListTemplate" DataType="{x:Type event:EventViewModel}">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="Auto" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>

       <TextBlock Text="{Binding Title, Converter={StaticResource EmptyStringConverter}, ConverterParameter='-'}" FontWeight="Bold" FontSize="14" />
        <TextBlock Text="{Binding Date, StringFormat={}{0:dd.MM.yyyy}}" Grid.Row="1" Grid.Column="0" FontStyle="Italic" />
        <Button Grid.Column="1" Grid.RowSpan="2" Grid.Row="0" Style="{DynamicResource ItemDeleteButton}" />
    </Grid>
</DataTemplate>

如何为我的 ListBoxItems 显示自定义错误模板?(我的目标是让物品的背景变成红色)

How can I display a custom error template for my ListBoxItems? (My goal is to make the background of the items red)

推荐答案

你也可以在ItemContainerStyle中对ListBoxItem指定Valdiation.ErrorTemplate:

You can specify Valdiation.ErrorTemplate on ListBoxItem as well in ItemContainerStyle:

<ListBox>
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="Validation.ErrorTemplate">
                <Setter.Value>
                    <ControlTemplate>
                        <Border Background="Red" Opacity="0.2">
                            <AdornedElementPlaceholder/>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

<小时>

当 item 中的任何属性引发错误时，您很可能希望在 ListBoxItem 上显示它.说 ListBoxItem 数据中绑定到 TextBox 的 Name 属性无效.在文本框上将 ValidatesOnDataErrors 设置为 true，并将 Validation.ValidationAdornerSite 设置为父 ListBoxItem.

---

Most likely you want to show it on ListBoxItem when any property in item throws an error. Say Name property in ListBoxItem data is invalid which is bind to TextBox. Set ValidatesOnDataErrors to true on textbox and set Validation.ValidationAdornerSite to parent ListBoxItem.

示例:

<ListBox>
    <ListBox.ItemTemplate>
        <DataTemplate>
            <TextBox Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}"
                     Validation.ValidationAdornerSite="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListBoxItem}}"/>
        </DataTemplate>
    </ListBox.ItemTemplate>
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="Validation.ErrorTemplate">
                <Setter.Value>
                    <ControlTemplate>
                        <Border Background="Red" Opacity="0.2">
                           <AdornedElementPlaceholder/>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

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