C#使用GDI中的API函数

　　我们知道在.NET 平台下主要是用ＧＤＩ＋来进行图形图像处理，在效率要求不高的情况下使用ＧＤＩ＋已经足够实现各种功能了，但一旦要求效率的情况下，我们可以考虑使用ＧＤＩ来代替ＧＤＩ＋，网上有人士做过相关测试（本人也测试过），GDI在图形、图像绘制方面效率较GDI+有很大提高。下面将自己开发过程中整理到的NativeGdi32Api类贴出来：

public static class NativeGdi32Api    {        [ DllImport("gdi32.dll" )]        public static extern int SetDIBits (IntPtr hdc, IntPtr hBitmap, int nStartScan , int nNumScans, IntPtr lpBits, IntPtr lpBI , int wUsage);        [ DllImport("gdi32.dll" )]        public static extern int SetDIBitsToDevice (IntPtr hdc, int x, int y , int dx, int dy, int SrcX, int SrcY, int Scan , int NumScans, IntPtr Bits, IntPtr BitsInfo , int wUsage);        [ DllImport("gdi32.dll" )]        public static extern IntPtr CreateDIBSection (IntPtr hdc, IntPtr pBitmapInfo, int un , IntPtr lplpVoid , IntPtr handle, int dw);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto )]        public static extern int SetPixel (IntPtr hdc, int x, int y , int crColor);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto )]        public static extern int GetPixel (IntPtr hdc, int x, int y );        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern int CombineRgn (IntPtr dest, IntPtr src1, IntPtr src2 , int flags);        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern IntPtr CreateBrushIndirect (ref LOGBRUSH brush );        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern IntPtr CreateRectRgnIndirect (ref RECTAPI rect );        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern int GetClipBox (IntPtr hDC, ref RECTAPI rectBox);        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern bool PatBlt (IntPtr hDC, int x, int y , int width, int height, uint flags);        [ DllImport("gdi32.dll" , CharSet= CharSet.Auto )]        public static extern int SelectClipRgn (IntPtr hDC, IntPtr hRgn);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr MoveToEx (IntPtr hDC, int x, int y , ref POINTAPI lpPoint );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr LineTo (IntPtr hDC, int x, int y );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreatePen (int nPenStyle, int nWidth, int crColor );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern int SetBrushOrgEx (IntPtr hDC, int x, int y , ref POINTAPI p );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreatePatternBrush (IntPtr hBMP);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern int GetTextFace (IntPtr hDC, int nCount, string lpFacename );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern int GetTextMetrics (IntPtr hDC, ref GDITextMetric TextMetric);        [ DllImport("gdi32.dll" , CharSet = CharSet.Ansi , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreateFontIndirect ([MarshalAs( UnmanagedType.LPStruct )]LogFont LogFont);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int BitBlt (IntPtr hDestDC, int x, int y , int nWidth, int nHeight, IntPtr hSrcDC , int xSrc, int ySrc, int dwRop );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreateSolidBrush (int crColor);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern int Rectangle (IntPtr hDC, int left, int top , int right, int bottom);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreateHatchBrush (int Style, int crColor);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreateCompatibleBitmap (IntPtr hDC, int nWidth, int nHeight );        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr CreateCompatibleDC (IntPtr hDC);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr SelectObject (IntPtr hDC, IntPtr hObject);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr DeleteObject (IntPtr hObject);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int GetTextColor (IntPtr hDC);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int SetTextColor (IntPtr hDC, int crColor);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int GetBkColor (IntPtr hDC);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int GetBkMode (IntPtr hDC);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern IntPtr DeleteDC (IntPtr hDC);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int SetBkColor (IntPtr hDC, int crColor);        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Auto, CallingConvention = CallingConvention .StdCall)]        public static extern int SetBkMode (IntPtr hDC, int Mode);        [ DllImport("gdi32.dll" , CharSet = CharSet.Auto , CallingConvention = CallingConvention .StdCall, SetLastError=true )]        public static extern int GdiFlush ();        [ DllImport("gdi32.dll" , SetLastError = true, CharSet = CharSet. Ansi, CallingConvention = CallingConvention .StdCall)]        public static extern int EnumFontFamiliesEx (IntPtr hDC, [MarshalAs(UnmanagedType .LPStruct)] LogFont lf , FONTENUMPROC proc, Int64 LParam, Int64 DW );        [ DllImport("gdi32.dll" , EntryPoint = "GdiAlphaBlend" )]        public static extern bool AlphaBlend (          IntPtr hdcDest ,                 // handle to destination DC          int nXOriginDest ,            // x-coord of upper-left corner          int nYOriginDest ,            // y-coord of upper-left corner          int nWidthDest ,              // destination width          int nHeightDest ,             // destination height          IntPtr hdcSrc ,                  // handle to source DC          int nXOriginSrc ,             // x-coord of upper-left corner          int nYOriginSrc ,             // y-coord of upper-left corner          int nWidthSrc ,               // source width          int nHeightSrc ,              // source height          BLENDFUNCTION blendFunction   // alpha-blending function        );    }

   另外，如果真的是对效率要求很高的应用，还是推荐大家使用OpenGL、DirectX。.NET平台下有与之对应的Tao.OpenGL和Managed DirectX。