我有一个System.Drawing.Bitmap实例,并希望将其以system . windows . media . image . bitmapimage的形式提供给我的WPF应用程序。
最好的方法是什么?
我有一个System.Drawing.Bitmap实例,并希望将其以system . windows . media . image . bitmapimage的形式提供给我的WPF应用程序。
最好的方法是什么?
当前回答
我花了一些时间让转换双向工作,所以这里是我提出的两个扩展方法:
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;
}
}
}
其他回答
感谢Hallgrim,以下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,而不是在我最初的问题中BitmapImage
通过编写自定义位图源,你可以在两个命名空间(Media和Drawing)之间共享像素数据。转换将立即进行,并且不会分配额外的内存。如果你不想显式地创建你的位图的副本,这是你想要的方法。
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
}
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();
}
我的观点来自于一些资源。https://stackoverflow.com/a/7035036 https://stackoverflow.com/a/1470182/360211
using System;
using System.Drawing;
using System.Runtime.ConstrainedExecution;
using System.Runtime.InteropServices;
using System.Security;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media.Imaging;
using Microsoft.Win32.SafeHandles;
namespace WpfHelpers
{
public static class BitmapToBitmapSource
{
public static BitmapSource ToBitmapSource(this Bitmap source)
{
using (var handle = new SafeHBitmapHandle(source))
{
return Imaging.CreateBitmapSourceFromHBitmap(handle.DangerousGetHandle(),
IntPtr.Zero, Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
}
}
[DllImport("gdi32")]
private static extern int DeleteObject(IntPtr o);
private sealed class SafeHBitmapHandle : SafeHandleZeroOrMinusOneIsInvalid
{
[SecurityCritical]
public SafeHBitmapHandle(Bitmap bitmap)
: base(true)
{
SetHandle(bitmap.GetHbitmap());
}
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
protected override bool ReleaseHandle()
{
return DeleteObject(handle) > 0;
}
}
}
}
我在一家图像供应商工作,写了一个WPF到我们的图像格式的适配器,它类似于System.Drawing.Bitmap。
我写了这个KB来向我们的客户解释:
http://www.atalasoft.com/kb/article.aspx?id=10156
这里有代码可以做到这一点。你需要用Bitmap替换AtalaImage,并做与我们正在做的相同的事情——这应该是相当简单的。