图片UriSource和数据绑定 [英] Image UriSource and Data Binding

问题描述

我想自定义对象的列表绑定到一个WPF图像是这样的：

I'm trying to bind a list of custom objects to a WPF Image like this:

<Image>
    <Image.Source>
        <BitmapImage UriSource="{Binding Path=ImagePath}" />
    </Image.Source>
</Image>

不过，这是行不通的。这是我收到的错误：

But it doesn't work. This is the error I'm getting:

属性UriSource'或财产'StreamSource的'必须设置。的

我在想什么？

推荐答案

的BitmapImage UriSource是甲流，我想，没有一个内置的转换器吧。

BitmapImage UriSource is a stream, i think, and there isn't a built in converter for it.

WPF有内置转换器某些共同的绑定。如果您绑定图像的源为一个字符串值，引擎盖下的WPF将使用值转换器的字符串，用于转换为URI，并获得BitmapImage的。

WPF has built in converters for certain common bindings. If you bind the Image's Source to a string value, underneath the hood WPF will use a value converter to convert the string to a URI, and get the BitmapImage from that.

所以，如果不是你这样做：

So if instead you did this:

<Image Source="{Binding ImageSource}" />

它的工作（如果ImageSource的财产是一个字符串，再一个有效的URI presentation到图像）

It would work (if the ImageSource property was a string representation of a valid uri to an image)

当然你也可以推出自己的，并在Silverlight你需要，因为问题的Image控件与绑定：

You can of course roll your own, and in Silverlight you need to because of issues the Image control has with Bindings:

public sealed class ImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType,
                          object parameter, CultureInfo culture)
    {
        try
        {
            return new BitmapImage(new Uri((string)value));
        }
        catch 
        {
            return new BitmapImage();
        }
    }

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

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