将System.Drawing.Bitmap转换为Direct2D.D2DBitmap

最近在尝试Direct2D编程，挺好玩的。

但是有时候还是会用到GDI+来生成图片，但D2D绘图需要用到自己的D2DBitmap类。

因此需要转换，查阅了下网上的资料，写了这么一个方法：

 1 using System;
 2 using System.Windows.Forms;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Diagnostics;
 6 using DX = SharpDX;
 7 using D2D = SharpDX.Direct2D1;
 8 using WIC = SharpDX.WIC;
 9 using DDW = SharpDX.DirectWrite;
10 using DXGI = SharpDX.DXGI;
11 using SharpDX;
12
13         public D2D.Bitmap ConvertFromSystemBitmap(System.Drawing.Bitmap bmp)
14         {
15             System.Drawing.Bitmap desBitmap;//预定义要是使用的bitmap
16             //如果原始的图像像素格式不是32位带alpha通道
17             //需要转换为32位带alpha通道的格式
18             //否则无法和Direct2D的格式对应
19             if (bmp.PixelFormat != System.Drawing.Imaging.PixelFormat.Format32bppPArgb)
20             {
21                 desBitmap = new System.Drawing.Bitmap(bmp.Width, bmp.Height, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
22                 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(desBitmap))
23                 {
24                     g.DrawImage(bmp, 0, 0);
25                 }
26             }
27             else
28             {
29                 desBitmap = bmp;
30             }
31
32
33             //直接内存copy会非常快
34             //如果使用循环逐点转换会非常慢
35             System.Drawing.Imaging.BitmapData bmpData = desBitmap.LockBits(
36                         new System.Drawing.Rectangle(0, 0, desBitmap.Width, desBitmap.Height),
37                         System.Drawing.Imaging.ImageLockMode.ReadOnly,
38                         desBitmap.PixelFormat
39                     );
40             int numBytes = bmpData.Stride * desBitmap.Height;
41             byte[] byteData = new byte[numBytes];
42             IntPtr ptr = bmpData.Scan0;
43             System.Runtime.InteropServices.Marshal.Copy(ptr, byteData, 0, numBytes);
44             desBitmap.UnlockBits(bmpData);
45
46
47
48             D2D.BitmapProperties bp;
49             D2D.PixelFormat pixelFormat = new D2D.PixelFormat(DXGI.Format.B8G8R8A8_UNorm, D2D.AlphaMode.Premultiplied);
50
51             bp = new D2D.BitmapProperties(
52                       pixelFormat,
53                       desBitmap.HorizontalResolution,
54                       desBitmap.VerticalResolution
55                     );
56             D2D.Bitmap tempBitmap = new D2D.Bitmap(_renderTarget, new Size2(desBitmap.Width, desBitmap.Height), bp);
57             tempBitmap.CopyFromMemory(byteData, bmpData.Stride);
58
59             return tempBitmap;
60         }

PS.这里我用的是SharpDX组件，因为微软的Windows API Code Pack，只更新到1.1,2010年后就不维护了