多绑定时的随机DependencyProperty.UnsetValue

public static readonly DependencyProperty MyProperty =
    DependencyProperty.Register("MyProperty", typeof(object), typeof(MyClass),
        new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault,
            new PropertyChangedCallback(OnMyPropertyChanged)));

private static void OnMyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    // 处理属性变化
}

public class MultiValueConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        foreach (var value in values)
        {
            if (value != DependencyProperty.UnsetValue)
            {
                return value;
            }
        }
        return null; // 或者返回一个默认值
    }

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

<Window.Resources>
    <local:MultiValueConverter x:Key="multiValueConverter"/>
</Window.Resources>

<TextBlock>
    <TextBlock.Text>
        <MultiBinding Converter="{StaticResource multiValueConverter}">
            <Binding Path="Source1"/>
            <Binding Path="Source2"/>
        </MultiBinding>
    </TextBlock.Text>
</TextBlock>