如果我使用IValueConverter
它可以工作,而IMultiValueConverter
返回相同的值却不能,这是为什么呢?
<Border Background="Red" Width="100" Height="100"
CornerRadius="{Binding Converter={vc:SingleAndMultiConverter}}" />
<Border Background="Red" Width="100" Height="100"
CornerRadius="{MultiBinding Converter={vc:SingleAndMultiConverter}}" />
public class SingleAndMultiConverter : MarkupExtension, IValueConverter, IMultiValueConverter
{
public override object ProvideValue(IServiceProvider serviceProvider)
{
return this;
}
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return Convert();
}
public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return Convert();
}
private object Convert()
{
return 15;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotSupportedException();
}
}
多重绑定会引发此错误:
BindingExpression 产生的值对目标属性无效。值='15'