【WPF】动态设置Binding的ConverterParameter转换器参数

问题：XAML中，想要在一个Bingding语句中再次Bingding。

Source="{Binding Path=Image,Converter={StaticResource UMatToBitmapSourceConverter},ConverterParameter={Binding IsMirror}}"

运行后会报错XML解析异常：

解决办法：改为使用MultiBinding的及其转换器。

<Image.Source>
    <MultiBinding Converter="{StaticResource UMatToBitmapSourceConverter}">
        <Binding Path="Image"/>
        <Binding Path="IsMirror"/>
    </MultiBinding>
</Image.Source>

多绑定的转换器，构造方法参数中object[] value即是多个Binding携带过来的值。用角标访问这些数据，注意向下转型的类型。

public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
    bool isMirror = false;
    if (values[1] != null)
    {
        isMirror = (bool)values[1];
    }
    try
    {
        if (values[0] is UMat)
        {
            var image = values[0] as UMat;
            return ChangeBitmapToImageSource(image.Bitmap, isMirror); // do what you want to do here！
        }
        else
        {
            return ChangeBitmapToImageSource(values[0] as System.Drawing.Bitmap);
        }
    }
    catch
    {
        return DependencyProperty.UnsetValue;
    }
}

---

重要参考：

• http://stackoverflow.com/questions/15309008/binding-converterparameter
• http://www.cnblogs.com/yanchanggang/archive/2009/10/30/1592692.html