C#截图相关代码

注明，本代码是转的。

我用了一下很好试，就留作将来用。

http://www.cnblogs.com/iwteih/archive/2010/01/15/1648318.html

http://hi.baidu.com/jordan51341/blog/item/203df4b4dd2710778ad4b272.html

***这是截图代码***

/// <summary>
    /// 提供全屏和指定窗口的截图 以及保存为文件的类
    /// </summary>
    public class ScreenCapture
    {
        /// <summary>
        /// 全屏截图 
        /// </summary>
        /// <returns></returns>
        public Image CaptureScreen()
        {
            return CaptureWindow( User32.GetDesktopWindow() );
        }
        /// <summary>
        /// 指定窗口截图
        /// </summary>
        /// <param name="handle">窗口句柄. (在windows应用程序中, 从Handle属性获得)</param>
        /// <returns></returns>
        public Image CaptureWindow(IntPtr handle)
        {
            IntPtr hdcSrc = User32.GetWindowDC(handle);
            User32.RECT windowRect = new User32.RECT();
            User32.GetWindowRect(handle,ref windowRect);
            int width = windowRect.right - windowRect.left;
            int height = windowRect.bottom - windowRect.top;
            IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);
            IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc,width,height);
            IntPtr hOld = GDI32.SelectObject(hdcDest,hBitmap);
            GDI32.BitBlt(hdcDest,0,0,width,height,hdcSrc,0,0,GDI32.SRCCOPY);
            GDI32.SelectObject(hdcDest,hOld);
            GDI32.DeleteDC(hdcDest);
            User32.ReleaseDC(handle,hdcSrc);
            Image img = Image.FromHbitmap(hBitmap);
            GDI32.DeleteObject(hBitmap);
            return img;
        }
        /// <summary>
        /// 指定窗口截图 保存为图片文件
        /// </summary>
        /// <param name="handle"></param>
        /// <param name="filename"></param>
        /// <param name="format"></param>
        public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)
        {
            Image img = CaptureWindow(handle);
            img.Save(filename,format);
        }
        /// <summary>
        /// 全屏截图 保存为文件
        /// </summary>
        /// <param name="filename"></param>
        /// <param name="format"></param>
        public void CaptureScreenToFile(string filename, ImageFormat format)
        {
            Image img = CaptureScreen();
            img.Save(filename,format);
        }
     
        /// <summary>
        /// 辅助类 定义 Gdi32 API 函数
        /// </summary>
        private class GDI32
        {
           
            public const int SRCCOPY = 0x00CC0020; 
            [DllImport("gdi32.dll")]
            public static extern bool BitBlt(IntPtr hObject,int nXDest,int nYDest,
                int nWidth,int nHeight,IntPtr hObjectSource,
                int nXSrc,int nYSrc,int dwRop);
            [DllImport("gdi32.dll")]
            public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC,int nWidth,
                int nHeight);
            [DllImport("gdi32.dll")]
            public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
            [DllImport("gdi32.dll")]
            public static extern bool DeleteDC(IntPtr hDC);
            [DllImport("gdi32.dll")]
            public static extern bool DeleteObject(IntPtr hObject);
            [DllImport("gdi32.dll")]
            public static extern IntPtr SelectObject(IntPtr hDC,IntPtr hObject);
        }

        /// <summary>
        /// 辅助类 定义User32 API函数
        /// </summary>
        private class User32
        {
            [StructLayout(LayoutKind.Sequential)]
            public struct RECT
            {
                public int left;
                public int top;
                public int right;
                public int bottom;
            }
            [DllImport("user32.dll")]
            public static extern IntPtr GetDesktopWindow();
            [DllImport("user32.dll")]
            public static extern IntPtr GetWindowDC(IntPtr hWnd);
            [DllImport("user32.dll")]
            public static extern IntPtr ReleaseDC(IntPtr hWnd,IntPtr hDC);
            [DllImport("user32.dll")]
            public static extern IntPtr GetWindowRect(IntPtr hWnd,ref RECT rect);
        }
    }

有时候需要截指定窗口的图，这时候就需要用寻找指定窗口代码

***寻找窗口的代码***

用法：FindWindow fw = new FindWindow(IntPtr.Zero, null, "ThunderDFrame", 10);//查找Title为ThunderDFrame的窗口，如果10秒内还没找到，返回false

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace Util
{
    class FindWindow
    {
        [DllImport("user32")]
        [return: MarshalAs(UnmanagedType.Bool)]
        //IMPORTANT : LPARAM  must be a pointer (InterPtr) in VS2005, otherwise an exception will be thrown
        private static extern bool EnumChildWindows(IntPtr window, EnumWindowProc callback, IntPtr i);
        //the callback function for the EnumChildWindows
        private delegate bool EnumWindowProc(IntPtr hWnd, IntPtr parameter);

        //if found  return the handle , otherwise return IntPtr.Zero
        [DllImport("user32.dll", EntryPoint = "FindWindowEx")]
        private static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

        private string m_classname; // class name to look for
        private string m_caption; // caption name to look for

        private DateTime start;
        private int m_timeout;//If exceed the time. Indicate no windows found.

        private IntPtr m_hWnd; // HWND if found
        public IntPtr FoundHandle
        {
            get { return m_hWnd; }
        }

        private bool m_IsTimeOut;
        public bool IsTimeOut
        {
            get{return m_IsTimeOut;}
            set { m_IsTimeOut = value; }
        }

        // ctor does the work--just instantiate and go
        public FindWindow(IntPtr hwndParent, string classname, string caption, int timeout)
        {
            m_hWnd = IntPtr.Zero;
            m_classname = classname;
            m_caption = caption;
            m_timeout = timeout;
            start = DateTime.Now;
            FindChildClassHwnd(hwndParent, IntPtr.Zero);
        }

        /**/
        /// <summary>
        /// Find the child window, if found m_classname will be assigned 
        /// </summary>
        /// <param name="hwndParent">parent's handle</param>
        /// <param name="lParam">the application value, nonuse</param>
        /// <returns>found or not found</returns>
        //The C++ code is that  lParam is the instance of FindWindow class , if found assign the instance's m_hWnd
        private bool FindChildClassHwnd(IntPtr hwndParent, IntPtr lParam)
        {
            EnumWindowProc childProc = new EnumWindowProc(FindChildClassHwnd);
            IntPtr hwnd = FindWindowEx(hwndParent, IntPtr.Zero, m_classname, m_caption);
            if (hwnd != IntPtr.Zero)
            {
                this.m_hWnd = hwnd; // found: save it
                m_IsTimeOut = false;
                return false; // stop enumerating
            }

            DateTime end = DateTime.Now;

            if (start.AddSeconds(m_timeout) > end)
            {
                m_IsTimeOut = true;
                return false;
            }

            EnumChildWindows(hwndParent, childProc, IntPtr.Zero); // recurse  redo FindChildClassHwnd
            return true;// keep looking
        }
    }
}