将FontWeight绑定到Silverlight中的布尔值

Question

Silverlight不具备DataTriggers功能,因此在这种情况下......有条件地将项目的字体权重设置为布尔值的最佳方法是什么？

例如......在Silverlight中无法实现以下功能.

<TextBlock Text="{Binding Text}">
    <TextBlock.Triggers>
        <DataTrigger Binding="{Binding IsDefault}" Value="True">
            <Setter Property="FontWeight" Value="Bold"/>
        </DataTrigger>
        <DataTrigger Binding="{Binding IsDefault}" Value="False">
            <Setter Property="FontWeight" Value="Normal"/>
        </DataTrigger>
    </TextBlock.Triggers>
</TextBlock>

谢谢!

Answer 1

您可以实现一个将bool转换为FontWeight的IValueConverter,并将其用作绑定的转换器:

<UserControl.Resources>
    <local:BoolToFontWeightConverter x:Key="boolToFontWeight"/>
</UserControl.Resources>

...

<TextBlock Text="{Binding Text}" FontWeight="{Binding IsDefault, Converter={StaticResource boolToFontWeight}}">

Answer 2

我实际上会使用布尔到样式转换器.

public class BoolToStyleConverter : IValueConverter
{
    public Style TrueStyle { get; set; }
    public Style FalseStyle { get; set; }

    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return ((bool)value) ? TrueStyle : FalseStyle;
    }

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

然后在资源部分中,您将设置2个公共样式属性.

<localHelpers:BoolToStyleConverter x:Key="boolToHistoryTextBlockStyleConverter">
    <localHelpers:BoolToStyleConverter.TrueStyle>
        <Style TargetType="TextBlock">
            <Setter Property="Foreground" Value="Red"></Setter>
        </Style>
    </localHelpers:BoolToStyleConverter.TrueStyle>
    <localHelpers:BoolToStyleConverter.FalseStyle>
        <Style TargetType="TextBlock">
            <Setter Property="Foreground" Value="Black"></Setter>
        </Style>
    </localHelpers:BoolToStyleConverter.FalseStyle>
</localHelpers:BoolToStyleConverter>

此示例设置Foreground颜色,但您可以设置任何样式.要绑定它,你可以设置转换器,在这种情况下,如果IsCommentChange为True,文本将为红色,如果为false,则为黑色.

    <TextBlock Name="tbComment" Text="{Binding Path=Comment,Mode=OneTime}"
 TextWrapping="Wrap"  
    Style="{Binding Path=IsCommentChanged, 
    Converter={StaticResource boolToHistoryTextBlockStyleConverter}}" />