使用 XAML 将 System.Drawing.Image 绑定到 System.Windows.Image 控件 [英] using XAML to bind to a System.Drawing.Image into a System.Windows.Image control

问题描述

我将一个 ListView 绑定到一个对象列表，就像这样；

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

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

我正在绑定一个声明两个属性的对象；

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

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

我想填充一个 DataTemplate 但我不知道如何；如果我在模板中执行此操作；

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>      

文字出现但图像没有.我究竟做错了什么?调试输出显示

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')

推荐答案

找到了一种令我满意的方式.使用 Reed Copsey 的指针 和 本教程 我已将代码包装为 IValueConverter.

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

这是从System.Drawing.Image到System.Windows.Media.ImageSource的转换器；

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;
        }
    }
}

然后需要将图片转换器作为资源导入XAML；

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>

然后你可以在XAML中使用它直接绑定到Image，使用新的转换器；

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} }" />

这篇关于使用 XAML 将 System.Drawing.Image 绑定到 System.Windows.Image 控件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！