python 截屏

1.python截屏的方法：方法一使用PIL库，方法二使用win32
PIL库截屏简单

2.PIL库截屏

coordinate = (0, 0, 60,20)
 pic = ImageGrab.grab(coordinate)

3.win32库截屏

def grab(dpath,args):
  ''''' 
参数为指定保存的目录 
  '''
  hwnd = 0
  hwndDC = win32gui.GetWindowDC(hwnd)  
  mfcDC=win32ui.CreateDCFromHandle(hwndDC)  
  saveDC=mfcDC.CreateCompatibleDC()  
  saveBitMap = win32ui.CreateBitmap()  
  MoniterDev=win32api.EnumDisplayMonitors(None,None) 
  #w = MoniterDev[0][2][2]
  #h = MoniterDev[0][2][3]
  w = args[2]
  h = args[3]
  #print w,h　　　#图片大小 
  saveBitMap.CreateCompatibleBitmap(mfcDC, w,h)
  saveDC.SelectObject(saveBitMap)  
  saveDC.BitBlt((0,0),(w, h) , mfcDC, (args[0],args[1]), win32con.SRCCOPY)
  cc=time.gmtime() 
  bmpname=str(cc[0])+str(cc[1])+str(cc[2])+str(cc[3]+8)+str(cc[4])+str(cc[5])+'.bmp'
  saveBitMap.SaveBitmapFile(saveDC, bmpname)
  pic = Image.open(bmpname)
  pic.save(os.path.join(dpath, 'xxxxx.jpeg'), 'jpeg')
  os.remove(bmpname)
  return pic

4.截屏的异常
无论是使用win32还是PIL截屏，如果是远程登录windows服务器，然后退出用户的情况下都会报错，
   PIL
  

File "E:\python-workspace\crawler-20150529\spiders\gz_spider.py", line 141, in _do_crawl_img_by_screenshot
    pic = ImageGrab.grab(coordinate)  # 截图
  File "D:\Python27\lib\site-packages\PIL\ImageGrab.py", line 34, in grab
    size, data = grabber()
IOError: screen grab failed

   win32
  

File "E:\python-workspace\crawler-20150529\spiders\sele.py", line 162, in _do_crawl_img
    img = self._do_crawl_img_by_screenshot()
  File "E:\python-workspace\crawler-20150529\spiders\sz_spider.py", line 149, in _do_crawl_img_by_screenshot
    pic = grab(self.storage_path,coordinate)
  File "E:\python-workspace\crawler-20150529\GrabUtil.py", line 24, in grab
    saveDC.BitBlt((0,0),(w, h) , mfcDC, (args[0],args[1]), win32con.SRCCOPY)
error: BitBlt failed

   错误原因：mstsc远程登录服务器的时候用户处于登录状态，断开远程界面用户处于登出状态，计算机无用户登录状态时整个屏幕是黑的，不能正常截屏

   解决方法：1.使用svc登录部署，这样用户一直处于登录状态。2.多用户登录，其中一个用户一直处于登录，部署时使用另一个用户部署