如何根据数据值修改DataGrid中Border的BorderBrush属性

实现步骤 #

1. 声明转换器资源
   在你的XAML根节点（如Window或UserControl）的资源字典中添加转换器实例，注意替换local为CellConverter所在的实际命名空间：

<Window.Resources>
    <!-- 替换clr-namespace为你的转换器所在命名空间 -->
    <local:CellConverter x:Key="CellConverter"/>
</Window.Resources>

2. 修改Border的BorderBrush绑定
   在DataGridRowStyle2的模板中，将DGR_Border的固定BorderBrush值替换为绑定到数据模型的目标属性，并应用转换器。假设数据模型中存储优先级的属性名为Priority，请替换为你实际的属性名：

修改后的完整Style代码：

<Style x:Key="DataGridRowStyle2" TargetType="{x:Type DataGridRow}">
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="SnapsToDevicePixels" Value="true"/>
    <Setter Property="BorderBrush" Value="Transparent"/>
    <Setter Property="ValidationErrorTemplate">
        <Setter.Value>
            <ControlTemplate>
                <TextBlock Foreground="Transparent" Margin="2,0,0,0" Text="!" VerticalAlignment="Center"/>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type DataGridRow}">
                <!-- 修改此处的BorderBrush绑定 -->
                <Border x:Name="DGR_Border" CornerRadius="5" 
                        Background="{TemplateBinding Background}" 
                        BorderThickness="2" 
                        BorderBrush="{Binding Priority, Converter={StaticResource CellConverter}}" 
                        SnapsToDevicePixels="True">
                    <SelectiveScrollingGrid>
                        <SelectiveScrollingGrid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="*"/>
                        </SelectiveScrollingGrid.ColumnDefinitions>
                        <SelectiveScrollingGrid.RowDefinitions>
                            <RowDefinition Height="*"/>
                            <RowDefinition Height="Auto"/>
                        </SelectiveScrollingGrid.RowDefinitions>
                        <DataGridCellsPresenter ItemsPanel="{TemplateBinding ItemsPanel}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                        <DataGridDetailsPresenter Visibility="{TemplateBinding DetailsVisibility}"/>
                        <DataGridRowHeader Visibility="{Binding HeadersVisibility, Converter={x:Static DataGrid.HeadersVisibilityConverter}, ConverterParameter={x:Static DataGridHeadersVisibility.Row}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
                    </SelectiveScrollingGrid>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

若需要明确指定绑定源为当前DataGridRow的DataContext，可使用RelativeSource：

BorderBrush="{Binding Path=Priority, RelativeSource={RelativeSource AncestorType={x:Type DataGridRow}}, Converter={StaticResource CellConverter}}"

3. 确认转换器代码
   你编写的CellConverter逻辑正确，无需修改，它会根据输入的字符串值返回对应的Brush：

public class CellConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        string input = value as string;
        switch (input)
        {
            case "High":
                return Brushes.Red;
            case "Medium":
                return Brushes.Yellow;
            case "Low":
                return Brushes.Green;
            default:
                return DependencyProperty.UnsetValue;
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

内容的提问来源于stack exchange，提问作者jirina