1
我想尝试一下能够有一个转换器,其参数可以与当前数据上下文绑定。任何人都可以告诉我为什么到达Convert()函数时,Source属性始终为空?从DependencyObject继承的自定义IValueConverter
namespace WpfApplication32
{
public class ConverterTest : DependencyObject, IValueConverter
{
public static readonly DependencyProperty SourceProperty =
DependencyProperty.Register("Source", typeof(DependencyObject), typeof(ConverterTest));
public DependencyObject Source
{
get { return (DependencyObject)this.GetValue(SourceProperty); }
set { this.SetValue(SourceProperty, value); }
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
return value;
}
}
public partial class MainWindow : Window
{
public MainWindow()
{
Value = 7;
InitializeComponent();
DataContext = this;
}
public float Value
{
get;
set;
}
}
}
<Window x:Class="WpfApplication32.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication32">
<Slider>
<Slider.Value>
<Binding Path="Value">
<Binding.Converter>
<local:ConverterTest Source="{Binding}"/>
</Binding.Converter>
</Binding>
</Slider.Value>
</Slider>
</Window>
谢谢,这似乎工作,但我不知道为什么。为什么原始代码不起作用?我觉得我缺少在你链接的解决方法之前需要的知识是有意义的。 – hammer
基本上,由于某种原因,Freezable继承了DataContext,而大部分资源和不属于可视树的部分都没有。他们很特别。这里..这解释更多http://drwpf.com/blog/2008/05/22/leveraging-freezables-to-provide-an-inheritance-context-for-bindings/ – Alan