秒大刀 博客

using System;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.ComponentModel;

using System.Collections;

using System.Windows.Forms;

using System.Data;

using System.Runtime.InteropServices;

namespace ymz

{

    /// <summary>

    /// 屏幕截取工具

    /// 调用WinGDI-API实现屏幕截取

    /// </summary>

    public class GetScreenTool

    {

        /// 截取全屏

        {

            return GetPartScreen(Point.Empty, Point.Empty, true);

        }

        /// 截取屏幕特定区域

          public static Bitmap GetScreen(Point p1, Point p2)

        {

            return GetPartScreen(p1, p2, false);

        }

        #region 实现

        /// 截取部分屏幕

        {

            IntPtr hscrdc,hmemdc;

            IntPtr hbitmap,holdbitmap;

            int nx,ny,nx2,ny2;

            nx=ny=nx2=ny2=0;

            int nwidth, nheight;

            int xscrn, yscrn;

            hscrdc = CreateDC("DISPLAY", null, null, 0);//创建DC句柄

            hmemdc = CreateCompatibleDC(hscrdc);//创建一个内存DC

            xscrn = GetDeviceCaps(hscrdc, 8/*HORZRES*/);//获取屏幕宽度//wingdi.h

            yscrn = GetDeviceCaps(hscrdc, 10/*VERTRES*/);//获取屏幕高度//wingdi.h

            if(Full)//如果是截取整个屏幕

            {

                nx = 0;

                ny = 0;

                nx2 = xscrn;

                ny2 = yscrn;

            }

            else

            {

                nx = P1.X;

                ny = P1.Y;

                nx2 =P2.X;

                ny2 =P2.Y;

                //检查数值合法性

                if(nx<0)nx = 0;

                if(ny<0)ny = 0;

                if(nx2>xscrn)nx2 = xscrn;

                if(ny2>yscrn)ny2 = yscrn;

            }

            nwidth = nx2 - nx;//截取范围的宽度

            nheight = ny2 - ny;//截取范围的高度

            hbitmap = CreateCompatibleBitmap(hscrdc, nwidth, nheight);//从内存DC复制到hbitmap句柄

            holdbitmap = SelectObject(hmemdc, hbitmap);

            BitBlt(hmemdc, 0, 0, nwidth, nheight,hscrdc, nx, ny,(UInt32)0xcc0020);

            hbitmap = SelectObject(hmemdc, holdbitmap);

            DeleteDC(hscrdc);//删除用过的对象

            DeleteDC(hmemdc);//删除用过的对象

            return Bitmap.FromHbitmap(hbitmap);//用Bitmap.FromHbitmap从hbitmap返回Bitmap

        }

        #region 所用到的API声明

        [DllImport("gdi32.dll")]

        private static extern IntPtr CreateDC(

            string lpszDriver,  

            string lpszDevice,   

            string lpszOutput,   

            Int64 lpInitData 

            );

        [DllImport("gdi32.dll")]

        private static extern IntPtr CreateCompatibleDC(

            IntPtr hdc

            );

        [DllImport("gdi32.dll")]

        private static extern int GetDeviceCaps(

            IntPtr hdc,    

            Int32 nIndex

            );

        [DllImport("gdi32.dll")]

        private static extern IntPtr CreateCompatibleBitmap(

            IntPtr hdc,       

            int nWidth,    

            int nHeight    

            );

        [DllImport("gdi32.dll")]

        private static extern IntPtr SelectObject(

            IntPtr hdc,       

            IntPtr hgdiobj  

            );

        [DllImport("gdi32.dll")]

        private static extern int BitBlt(

            IntPtr hdcDest,

            int nXDest, 

            int nYDest, 

            int nWidth, 

            int nHeight,

            IntPtr hdcSrc, 

            int nXSrc,  

            int nYSrc,  

            UInt32 dwRop 

            );

        [DllImport("gdi32.dll")]

        private static extern int DeleteDC(

            IntPtr hdc         

            );

        #endregion

        #endregion