利用PrintWindow打印后台窗口后遇到的疑问

[取昵称麻烦]

PrintWindow只能用于窗口，不能打印控件。
如果我先把整个窗口打印到一个Bitmap中，再从中复制控件区域，或者指定区域的图像，请问怎么做？

[kye_jufei]

這是C#中實現的結果，你可以使用DELPHI，用它的API聲明這個DLL並調用即可。。。

只要窗体的visable为true，即使它在屏幕的外面也可以抓到图。如果为false，就是一张黑图了，赫赫。

public   static   Bitmap   GetWindow(IntPtr   hWnd) 
    { 
      IntPtr   hscrdc   =   GetWindowDC(hWnd); 
      Control   control   =   Control.FromHandle(hWnd); 
      IntPtr   hbitmap   =   CreateCompatibleBitmap(hscrdc,   control.Width,   control.Height); 
      IntPtr   hmemdc   =   CreateCompatibleDC(hscrdc); 
      SelectObject(hmemdc,   hbitmap); 
      PrintWindow(hWnd,   hmemdc,   0); 
      Bitmap   bmp   =   Bitmap.FromHbitmap(hbitmap); 
      DeleteDC(hscrdc);//删除用过的对象 
      DeleteDC(hmemdc);//删除用过的对象 
      return   bmp; 
    } 

API声明 

[DllImport( "gdi32.dll ")] 
    public   static   extern   IntPtr   CreateDC( 
      string   lpszDriver,                 //   driver   name驱动名 
      string   lpszDevice,                 //   device   name设备名 
      string   lpszOutput,                 //   not   used;   should   be   NULL 
      IntPtr   lpInitData     //   optional   printer   data 
      ); 
    [DllImport( "gdi32.dll ")] 
    public   static   extern   int   BitBlt( 
      IntPtr   hdcDest,   //   handle   to   destination   DC目标设备的句柄 
      int   nXDest,     //   x-coord   of   destination   upper-left   corner目标对象的左上角的X坐标 
      int   nYDest,     //   y-coord   of   destination   upper-left   corner目标对象的左上角的Y坐标 
      int   nWidth,     //   width   of   destination   rectangle目标对象的矩形宽度 
      int   nHeight,   //   height   of   destination   rectangle目标对象的矩形长度 
      IntPtr   hdcSrc,     //   handle   to   source   DC源设备的句柄 
      int   nXSrc,       //   x-coordinate   of   source   upper-left   corner源对象的左上角的X坐标 
      int   nYSrc,       //   y-coordinate   of   source   upper-left   corner源对象的左上角的Y坐标 
      UInt32   dwRop     //   raster   operation   code光栅的操作值 
      ); 

    [DllImport( "gdi32.dll ")] 
    public   static   extern   IntPtr   CreateCompatibleDC( 
      IntPtr   hdc   //   handle   to   DC 
      ); 

    [DllImport( "gdi32.dll ")] 
    public   static   extern   IntPtr   CreateCompatibleBitmap( 
      IntPtr   hdc,                 //   handle   to   DC 
      int   nWidth,           //   width   of   bitmap,   in   pixels 
      int   nHeight           //   height   of   bitmap,   in   pixels 
      ); 

    [DllImport( "gdi32.dll ")] 
    public   static   extern   IntPtr   SelectObject( 
      IntPtr   hdc,                     //   handle   to   DC 
      IntPtr   hgdiobj       //   handle   to   object 
      ); 

    [DllImport( "gdi32.dll ")] 
    public   static   extern   int   DeleteDC( 
      IntPtr   hdc                     //   handle   to   DC 
      ); 

    [DllImport( "user32.dll ")] 
    public   static   extern   bool   PrintWindow( 
      IntPtr   hwnd,                               //   Window   to   copy,Handle   to   the   window   that   will   be   copied.   
      IntPtr     hdcBlt,                           //   HDC   to   print   into,Handle   to   the   device   context.   
      UInt32   nFlags                             //   Optional   flags,Specifies   the   drawing   options.   It   can   be   one   of   the   following   values.   
      ); 

    [DllImport( "user32.dll ")] 
    public   static   extern   IntPtr   GetWindowDC( 
      IntPtr   hwnd 
      ); 

[取昵称麻烦]

谢谢你的回复

[取昵称麻烦]

唉，没落了，没人知道