WPF-将位图转换为ImageSource

本文关键字：ImageSource 转换 位图 WPF- | 更新日期: 2023-09-27 18:25:54

我需要将System.Drawing.Bitmap转换为System.Windows.Media.ImageSource类，以便将其绑定到WizardPage（扩展WPF工具包）的HeaderImage控件中。位图被设置为我编写的程序集的资源。它被这样引用：

public Bitmap GetBitmap
{
   get
   {
      Bitmap bitmap = new Bitmap(Resources.my_banner);
      return bitmap;
   }
}
public ImageSource HeaderBitmap
{
   get
   {
      ImageSourceConverter c = new ImageSourceConverter();
      return (ImageSource)c.ConvertFrom(GetBitmap);
   }
}

转换器是我在这里找到的。我在收到一个NullReferenceException

return (ImageSource) c.ConvertFrom(Resources.my_banner);

如何初始化ImageSource以避免此异常？或者还有别的办法吗？我想以后使用它，就像：

<xctk:WizardPage x:Name="StartPage" Height="500" Width="700"
                 HeaderImage="{Binding HeaderBitmap}" 
                 Enter="StartPage_OnEnter"

提前感谢您的回答。

WPF-将位图转换为ImageSource

对于其他人，这是有效的：

    //If you get 'dllimport unknown'-, then add 'using System.Runtime.InteropServices;'
    [DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool DeleteObject([In] IntPtr hObject);
    public ImageSource ImageSourceFromBitmap(Bitmap bmp)
    {
        var handle = bmp.GetHbitmap();
        try
        {
            return Imaging.CreateBitmapSourceFromHBitmap(handle, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
        }
        finally { DeleteObject(handle); }               
    }

为了搜索人员的利益，我基于这个更详细的解决方案创建了一个快速转换器。

到目前为止没有问题。

using System;
using System.Drawing;
using System.IO;
using System.Windows.Media.Imaging;
namespace XYZ.Helpers
{
    public class ConvertBitmapToBitmapImage
    {
        /// <summary>
        /// Takes a bitmap and converts it to an image that can be handled by WPF ImageBrush
        /// </summary>
        /// <param name="src">A bitmap image</param>
        /// <returns>The image as a BitmapImage for WPF</returns>
        public BitmapImage Convert(Bitmap src)
        {
            MemoryStream ms = new MemoryStream();
            ((System.Drawing.Bitmap)src).Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
            BitmapImage image = new BitmapImage();
            image.BeginInit();
            ms.Seek(0, SeekOrigin.Begin);
            image.StreamSource = ms;
            image.EndInit();
            return image;
        }
    }
}

我不相信ImageSourceConverter会从System.Drawing.Bitmap转换而来。但是，您可以使用以下内容：

public static BitmapSource CreateBitmapSourceFromGdiBitmap(Bitmap bitmap)
{
    if (bitmap == null)
        throw new ArgumentNullException("bitmap");
    var rect = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
    var bitmapData = bitmap.LockBits(
        rect,
        ImageLockMode.ReadWrite,
        PixelFormat.Format32bppArgb);
    try
    {
        var size = (rect.Width * rect.Height) * 4;
        return BitmapSource.Create(
            bitmap.Width,
            bitmap.Height,
            bitmap.HorizontalResolution,
            bitmap.VerticalResolution,
            PixelFormats.Bgra32,
            null,
            bitmapData.Scan0,
            size,
            bitmapData.Stride);
    }
    finally
    {
        bitmap.UnlockBits(bitmapData);
    }
}

该解决方案要求源图像为Bgra32格式；如果您正在处理其他格式，则可能需要添加转换。

dethSwatch-感谢您的回答！它帮助很大！在实现它之后，我得到了所需的行为，但我发现我在程序的另一部分遇到了内存/句柄问题。我按如下方式更改了代码，使其更加详细，问题就消失了。再次感谢！

    [DllImport("gdi32.dll", EntryPoint = "DeleteObject")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool DeleteObject([In] IntPtr hObject);
    public ImageSource ImageSourceForBitmap(Bitmap bmp)
    {
        var handle = bmp.GetHbitmap();
        try
        {
            ImageSource newSource = Imaging.CreateBitmapSourceFromHBitmap(handle, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
            DeleteObject(handle);
            return newSource;
        }
        catch (Exception ex)
        {
            DeleteObject(handle);
            return null;
        }
    }

void Draw()
{
    System.Drawing.Bitmap bmp = new Bitmap();
    ...
    Image img = new Image();
    img.Source = BitmapToImageSource(bmp)
 }

private BitmapImage BitmapToImageSource(System.Drawing.Bitmap bitmap)
{
    using (MemoryStream memory = new MemoryStream())
    {
        bitmap.Save(memory, System.Drawing.Imaging.ImageFormat.Bmp);
        memory.Position = 0;
        BitmapImage bitmapimage = new BitmapImage();
        bitmapimage.BeginInit();
        bitmapimage.StreamSource = memory;
        bitmapimage.CacheOption = BitmapCacheOption.OnLoad;
        bitmapimage.EndInit();
        return bitmapimage;
    }
}

对我来说最简单的解决方案：

ImageBrush myBrush = new ImageBrush();
var bitmap = System.Drawing.Image.FromFile("pic1.bmp");
Bitmap bitmap = new System.Drawing.Bitmap(image);//it is in the memory now
var bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(bitmap.GetHbitmap(),IntPtr.Zero,Int32Rect.Empty,BitmapSizeOptions.FromEmptyOptions());
myBrush.ImageSource = bitmapSource;
cover.MainGrid.Background = myBrush;
cover.Show();
bitmap.Dispose();
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