将IValueConverter与DynamicResource一起使用？

Question

有没有办法在使用DynamicResource扩展时定义转换器？有些东西

<RowDefinition Height="{Binding Source={DynamicResource someHeight}, Converter={StaticResource gridLengthConverter}}" />

不幸的是,这给了我以下的重复:

无法在"绑定"类型的"Source"属性上设置"DynamicResourceExtension".'DynamicResourceExtension'只能在DependencyObject的DependencyProperty上设置.

Answer 1

我知道我到目前为止已经很晚了,但绝对有效的是像这样使用动态资源的BindingProxy

<my:BindingProxy x:Key="someHeightProxy" Data="{DynamicResource someHeight}" />

然后将转换器应用于代理

<RowDefinition Height="{Binding Source={StaticResource someHeightProxy}, Path=Data, Converter={StaticResource gridLengthConverter}}" />

Answer 2

尝试这样的事情：

标记扩展：

public class DynamicResourceWithConverterExtension : DynamicResourceExtension
{
    public DynamicResourceWithConverterExtension()
    {
    }

    public DynamicResourceWithConverterExtension(object resourceKey)
            : base(resourceKey)
    {
    }

    public IValueConverter Converter { get; set; }
    public object ConverterParameter { get; set; }

    public override object ProvideValue(IServiceProvider provider)
    {
        object value = base.ProvideValue(provider);
        if (value != this && Converter != null)
        {
            Type targetType = null;
            var target = (IProvideValueTarget)provider.GetService(typeof(IProvideValueTarget));
            if (target != null)
            {
                DependencyProperty targetDp = target.TargetProperty as DependencyProperty;
                if (targetDp != null)
                {
                    targetType = targetDp.PropertyType;
                }
            }
            if (targetType != null)
                return Converter.Convert(value, targetType, ConverterParameter, CultureInfo.CurrentCulture);
        }

        return value;
    }
}

XAML：

<RowDefinition Height="{my:DynamicResourceWithConverter someHeight, Converter={StaticResource gridLengthConverter}}" />