从System.Drawing.Bitmap加载WPF BitmapImage

Question

我有一个a的实例,System.Drawing.Bitmap并希望以一种形式将它提供给我的WPF应用程序System.Windows.Media.Imaging.BitmapImage.

对此最好的方法是什么？

Answer 1

如何从MemoryStream加载它？

using(MemoryStream memory = new MemoryStream())
{
    bitmap.Save(memory, ImageFormat.Png);
    memory.Position = 0;
    BitmapImage bitmapImage = new BitmapImage();
    bitmapImage.BeginInit();
    bitmapImage.StreamSource = memory;
    bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
    bitmapImage.EndInit();
}

Answer 2

感谢Hallgrim,这是我最终得到的代码:

ScreenCapture = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
   bmp.GetHbitmap(), 
   IntPtr.Zero, 
   System.Windows.Int32Rect.Empty, 
   BitmapSizeOptions.FromWidthAndHeight(width, height));

我也最终绑定到BitmapSource而不是像我原来的问题中的BitmapImage

Answer 3

我知道这已经得到了解答,但这里有一些扩展方法(适用于.NET 3.0+)进行转换.:)

        /// <summary>
    /// Converts a <see cref="System.Drawing.Image"/> into a WPF <see cref="BitmapSource"/>.
    /// </summary>
    /// <param name="source">The source image.</param>
    /// <returns>A BitmapSource</returns>
    public static BitmapSource ToBitmapSource(this System.Drawing.Image source)
    {
        System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(source);

        var bitSrc = bitmap.ToBitmapSource();

        bitmap.Dispose();
        bitmap = null;

        return bitSrc;
    }

    /// <summary>
    /// Converts a <see cref="System.Drawing.Bitmap"/> into a WPF <see cref="BitmapSource"/>.
    /// </summary>
    /// <remarks>Uses GDI to do the conversion. Hence the call to the marshalled DeleteObject.
    /// </remarks>
    /// <param name="source">The source bitmap.</param>
    /// <returns>A BitmapSource</returns>
    public static BitmapSource ToBitmapSource(this System.Drawing.Bitmap source)
    {
        BitmapSource bitSrc = null;

        var hBitmap = source.GetHbitmap();

        try
        {
            bitSrc = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                hBitmap,
                IntPtr.Zero,
                Int32Rect.Empty,
                BitmapSizeOptions.FromEmptyOptions());
        }
        catch (Win32Exception)
        {
            bitSrc = null;
        }
        finally
        {
            NativeMethods.DeleteObject(hBitmap);
        }

        return bitSrc;
    }

和NativeMethods类(安抚FxCop)

    /// <summary>
/// FxCop requires all Marshalled functions to be in a class called NativeMethods.
/// </summary>
internal static class NativeMethods
{
    [DllImport("gdi32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool DeleteObject(IntPtr hObject);
}

Answer 4

我花了一些时间让转换工作在两个方面,所以这里是我提出的两种扩展方法:

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Media.Imaging;

public static class BitmapConversion {

    public static Bitmap ToWinFormsBitmap(this BitmapSource bitmapsource) {
        using (MemoryStream stream = new MemoryStream()) {
            BitmapEncoder enc = new BmpBitmapEncoder();
            enc.Frames.Add(BitmapFrame.Create(bitmapsource));
            enc.Save(stream);

            using (var tempBitmap = new Bitmap(stream)) {
                // According to MSDN, one "must keep the stream open for the lifetime of the Bitmap."
                // So we return a copy of the new bitmap, allowing us to dispose both the bitmap and the stream.
                return new Bitmap(tempBitmap);
            }
        }
    }

    public static BitmapSource ToWpfBitmap(this Bitmap bitmap) {
        using (MemoryStream stream = new MemoryStream()) {
            bitmap.Save(stream, ImageFormat.Bmp);

            stream.Position = 0;
            BitmapImage result = new BitmapImage();
            result.BeginInit();
            // According to MSDN, "The default OnDemand cache option retains access to the stream until the image is needed."
            // Force the bitmap to load right now so we can dispose the stream.
            result.CacheOption = BitmapCacheOption.OnLoad;
            result.StreamSource = stream;
            result.EndInit();
            result.Freeze();
            return result;
        }
    }
}

Answer 5

最简单的方法是如果你可以直接从文件中制作WPF位图.

否则,您将不得不使用System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap.

Answer 6

// at class level;
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);    // https://stackoverflow.com/a/1546121/194717


/// <summary> 
/// Converts a <see cref="System.Drawing.Bitmap"/> into a WPF <see cref="BitmapSource"/>. 
/// </summary> 
/// <remarks>Uses GDI to do the conversion. Hence the call to the marshalled DeleteObject. 
/// </remarks> 
/// <param name="source">The source bitmap.</param> 
/// <returns>A BitmapSource</returns> 
public static System.Windows.Media.Imaging.BitmapSource ToBitmapSource(this System.Drawing.Bitmap source)
{
    var hBitmap = source.GetHbitmap();
    var result = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, System.Windows.Int32Rect.Empty, System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

    DeleteObject(hBitmap);

    return result;
}

Answer 7

我在一家成像供应商工作,并为我们的图像格式编写了一个WPF适配器,类似于System.Drawing.Bitmap.

我写了这篇KB来向客户解释:

http://www.atalasoft.com/kb/article.aspx?id=10156

那里有代码可以做到.你需要用Bitmap替换AtalaImage并做我们正在做的事情 - 它应该非常简单.

Answer 8

您只需编写自定义位图源，即可在两个名称空间（媒体和图形）之间共享pixeldata。转换将立即发生，并且不会分配额外的内存。如果您不想显式创建位图的副本，则可以使用这种方法。

class SharedBitmapSource : BitmapSource, IDisposable
{
    #region Public Properties

    /// <summary>
    /// I made it public so u can reuse it and get the best our of both namespaces
    /// </summary>
    public Bitmap Bitmap { get; private set; }

    public override double DpiX { get { return Bitmap.HorizontalResolution; } }

    public override double DpiY { get { return Bitmap.VerticalResolution; } }

    public override int PixelHeight { get { return Bitmap.Height; } }

    public override int PixelWidth { get { return Bitmap.Width; } }

    public override System.Windows.Media.PixelFormat Format { get { return ConvertPixelFormat(Bitmap.PixelFormat); } }

    public override BitmapPalette Palette { get { return null; } }

    #endregion

    #region Constructor/Destructor

    public SharedBitmapSource(int width, int height,System.Drawing.Imaging.PixelFormat sourceFormat)
        :this(new Bitmap(width,height, sourceFormat) ) { }

    public SharedBitmapSource(Bitmap bitmap)
    {
        Bitmap = bitmap;
    }

    // Use C# destructor syntax for finalization code.
    ~SharedBitmapSource()
    {
        // Simply call Dispose(false).
        Dispose(false);
    }

    #endregion

    #region Overrides

    public override void CopyPixels(Int32Rect sourceRect, Array pixels, int stride, int offset)
    {
        BitmapData sourceData = Bitmap.LockBits(
        new Rectangle(sourceRect.X, sourceRect.Y, sourceRect.Width, sourceRect.Height),
        ImageLockMode.ReadOnly,
        Bitmap.PixelFormat);

        var length = sourceData.Stride * sourceData.Height;

        if (pixels is byte[])
        {
            var bytes = pixels as byte[];
            Marshal.Copy(sourceData.Scan0, bytes, 0, length);
        }

        Bitmap.UnlockBits(sourceData);
    }

    protected override Freezable CreateInstanceCore()
    {
        return (Freezable)Activator.CreateInstance(GetType());
    }

    #endregion

    #region Public Methods

    public BitmapSource Resize(int newWidth, int newHeight)
    {
        Image newImage = new Bitmap(newWidth, newHeight);
        using (Graphics graphicsHandle = Graphics.FromImage(newImage))
        {
            graphicsHandle.InterpolationMode = InterpolationMode.HighQualityBicubic;
            graphicsHandle.DrawImage(Bitmap, 0, 0, newWidth, newHeight);
        }
        return new SharedBitmapSource(newImage as Bitmap);
    }

    public new BitmapSource Clone()
    {
        return new SharedBitmapSource(new Bitmap(Bitmap));
    }

    //Implement IDisposable.
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    #endregion

    #region Protected/Private Methods

    private static System.Windows.Media.PixelFormat ConvertPixelFormat(System.Drawing.Imaging.PixelFormat sourceFormat)
    {
        switch (sourceFormat)
        {
            case System.Drawing.Imaging.PixelFormat.Format24bppRgb:
                return PixelFormats.Bgr24;

            case System.Drawing.Imaging.PixelFormat.Format32bppArgb:
                return PixelFormats.Pbgra32;

            case System.Drawing.Imaging.PixelFormat.Format32bppRgb:
                return PixelFormats.Bgr32;

        }
        return new System.Windows.Media.PixelFormat();
    }

    private bool _disposed = false;

    protected virtual void Dispose(bool disposing)
    {
        if (!_disposed)
        {
            if (disposing)
            {
                // Free other state (managed objects).
            }
            // Free your own state (unmanaged objects).
            // Set large fields to null.
            _disposed = true;
        }
    }

    #endregion
}