使用XAML绑定到System.Drawing.Image对象变成System.Windows.Image控制 [英] using XAML to bind to a System.Drawing.Image into a System.Windows.Image control

问题描述

我一个ListView绑定到对象的列表，像这样;

 ＆LT; ListView控件
    的ItemsSource ={绑定路径=}
    的ItemTemplate ={DynamicResource EventTemplate}＆GT;
 

我绑定到该声明两个属性的对象;

 字符串显示名称{搞定; }
System.Drawing.Image对象图像{搞定;组; }
 

我想填充的DataTemplate ，但我无法弄清楚如何;如果我这样做，我的模板;

 ＆LT; StackPanel的方向=横向＆GT;
    ＆lt;图像来源={绑定路径=图片}/＆GT;
    ＆LT; TextBlock的文本={绑定路径=显示名称}/＆GT;
＆LT; / StackPanel的＆GT;
 

文本出现，但图像没有。我究竟做错了什么？调试输出显示

  System.Windows.Data错误：1：无法创建默认的转换器
执行类型之间的'单向'的转换
System.Drawing.Image对象和System.Windows.Media.ImageSource。
考虑使用绑定的转换器属性。
BindingEx pression：路径=图片;的DataItem ='RealElement
（哈希code = 54308798）;目标元素是'图像'（名称=''）;
target属性是源（类型'的ImageSource'）
 

解决方案

找到了一种方法我很高兴。使用<一个href=\"http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/833ca60f-6a11-4836-bb2b-ef779dfe3ff0/\">Reed •科普塞的指针和本教程我包裹code作为的IValueConverter 。

下面是从为System.Drawing.Image 来转换器 System.Windows.Media.ImageSource ;

 使用系统;
使用System.Drawing.Imaging;
使用System.Globalization;
使用System.IO;
使用System.Windows.Data;命名空间System.Windows.Media
{
    ///＆LT;总结＆gt;
    ///单向转换器从System.Drawing.Image对象到System.Windows.Media.ImageSource
    ///＆LT; /总结＆gt;
    [ValueConversion（typeof运算（System.Drawing.Image对象）的typeof（System.Windows.Media.ImageSource））]
    公共类ImageConverter：的IValueConverter
    {
        公共对象转换（对象的值，类型TARGETTYPE，
            对象参数，CultureInfo的文化）
        {
            //空图像空...
            如果（价值== NULL）{返回NULL; }            VAR图像=（System.Drawing.Image对象）值;
            //图像的WinForms我们想从WPF图像...
            VAR位=新System.Windows.Media.Imaging.BitmapImage（）;
            bitmap.BeginInit（）;
            MemoryStream的MemoryStream的=新的MemoryStream（）;
            //保存到内存流...
            image.Save（MemoryStream的，ImageFormat.Bmp）;
            //倒带流...
            memoryStream.Seek（0，System.IO.SeekOrigin.Begin）;
            bitmap.StreamSource = MemoryStream的;
            bitmap.EndInit（）;
            返回位图;
        }        公共对象ConvertBack（对象的值，类型TARGETTYPE，
            对象参数，CultureInfo的文化）
        {
            返回null;
        }
    }
}
 

然后，你需要把图像转换成XAML作为一种资源;

 的xmlns：医学版=CLR的命名空间：System.Windows.Media
...＆LT; ListView.Resources＆GT;
    ＆LT;配有：ImageConverter X：键=imageConverter/＆GT;
＆LT; /ListView.Resources>
 

然后，你可以用它在XAML直接绑定到图像，使用新的转换器;

 ＆lt;图像来源={绑定路径=图像，转换器= {StaticResource的imageConverter}}/＆GT;
 

I'm binding a ListView to a list of objects, like so;

<ListView 
    ItemsSource="{ Binding Path=. }"
    ItemTemplate="{DynamicResource EventTemplate}">   

I'm binding to an object which declares two properties;

string DisplayName { get; }
System.Drawing.Image Image { get; set; }

I want to populate a DataTemplate but I can't figure out how; if I do this in my template;

<StackPanel Orientation="Horizontal">
    <Image Source="{ Binding Path=Image }" />
    <TextBlock Text="{ Binding Path=DisplayName }" />
</StackPanel>      

The text appears but the image does not. What am I doing wrong? The debug output shows

System.Windows.Data Error: 1 : Cannot create default converter
to perform 'one-way' conversions between types
'System.Drawing.Image' and 'System.Windows.Media.ImageSource'.
Consider using Converter property of Binding.
BindingExpression:Path=Image; DataItem='RealElement'
(HashCode=54308798); target element is 'Image' (Name='');
target property is 'Source' (type 'ImageSource')

解决方案

Found a way I'm happy with. Using Reed Copsey's pointer and this tutorial I've wrapped the code as a IValueConverter.

Here's the converter from System.Drawing.Image to System.Windows.Media.ImageSource;

using System;
using System.Drawing.Imaging;
using System.Globalization;
using System.IO;
using System.Windows.Data;

namespace System.Windows.Media
{
    /// <summary>
    /// One-way converter from System.Drawing.Image to System.Windows.Media.ImageSource
    /// </summary>
    [ValueConversion(typeof(System.Drawing.Image), typeof(System.Windows.Media.ImageSource))]
    public class ImageConverter : IValueConverter
    {
        public object Convert(object value, Type targetType,
            object parameter, CultureInfo culture)
        {
            // empty images are empty...
            if (value == null) { return null; }

            var image = (System.Drawing.Image)value;
            // Winforms Image we want to get the WPF Image from...
            var bitmap = new System.Windows.Media.Imaging.BitmapImage();
            bitmap.BeginInit();
            MemoryStream memoryStream = new MemoryStream();
            // Save to a memory stream...
            image.Save(memoryStream, ImageFormat.Bmp);
            // Rewind the stream...
            memoryStream.Seek(0, System.IO.SeekOrigin.Begin);
            bitmap.StreamSource = memoryStream;
            bitmap.EndInit();
            return bitmap;
        }

        public object ConvertBack(object value, Type targetType,
            object parameter, CultureInfo culture)
        {
            return null;
        }
    }
}

Then you need to bring the image converter into XAML as a resource;

xmlns:med="clr-namespace:System.Windows.Media"
...

<ListView.Resources>
    <med:ImageConverter x:Key="imageConverter" />
</ListView.Resources>

Then you can use it in XAML to bind directly to the Image, using the new converter;

<Image Source="{ Binding Path=Image, Converter={StaticResource imageConverter} }" />

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