我正在使用pywin32的演示win32gui_taskbar.py&如果特定窗口当前是活动/前景窗口，则将其扩展为拍摄该窗口的屏幕截图。每当用户左键点击系统托盘图标时，就会调用screen_shot函数
import win32api, win32service
import win32gui, win32ui
import win32con, winerror
import sys, os
import time
from PIL import Image
class MainWindow:
def __init__(self):
msg_TaskbarRestart = win32gui.RegisterWindowMessage("TaskbarCreated");
message_map = {
msg_TaskbarRestart: self.OnRestart,
win32con.WM_DESTROY: self.OnDestroy,
win32con.WM_COMMAND: self.OnCommand,
win32con.WM_USER+20 : self.OnTaskbarNotify,
}
# Register the Window class.
wc = win32gui.WNDCLASS()
hinst = wc.hInstance = win32api.GetModuleHandle(None)
wc.lpszClassName = "PythonTaskbarDemo"
wc.style = win32con.CS_VREDRAW | win32con.CS_HREDRAW;
wc.hCursor = win32api.LoadCursor( 0, win32con.IDC_ARROW )
wc.hbrBackground = win32con.COLOR_WINDOW
wc.lpfnWndProc = message_map # could also specify a wndproc.
# Don't blow up if class already registered to make testing easier
try:
classAtom = win32gui.RegisterClass(wc)
except win32gui.error, err_info:
if err_info.winerror!=winerror.ERROR_CLASS_ALREADY_EXISTS:
raise
# Create the Window.
style = win32con.WS_OVERLAPPED | win32con.WS_SYSMENU
self.hwnd = win32gui.CreateWindow( wc.lpszClassName, "Taskbar Demo", style,
0, 0, win32con.CW_USEDEFAULT, win32con.CW_USEDEFAULT,
0, 0, hinst, None)
win32gui.UpdateWindow(self.hwnd)
self._DoCreateIcons()
def _DoCreateIcons(self):
# Try and find a custom icon
hinst = win32api.GetModuleHandle(None)
iconPathName = os.path.abspath(os.path.join( os.path.split(sys.executable)[0], "pyc.ico" ))
if not os.path.isfile(iconPathName):
# Look in DLLs dir, a-la py 2.5
iconPathName = os.path.abspath(os.path.join( os.path.split(sys.executable)[0], "DLLs",
"pyc.ico" ))
if not os.path.isfile(iconPathName):
# Look in the source tree.
iconPathName = os.path.abspath(os.path.join( os.path.split(sys.executable)[0], "..\PC
pyc.ico" ))
if os.path.isfile(iconPathName):
icon_flags = win32con.LR_LOADFROMFILE | win32con.LR_DEFAULTSIZE
hicon = win32gui.LoadImage(hinst, iconPathName, win32con.IMAGE_ICON, 0, 0, icon_flags)
else:
print "Can't find a Python icon file - using default"
hicon = win32gui.LoadIcon(0, win32con.IDI_APPLICATION)
flags = win32gui.NIF_ICON | win32gui.NIF_MESSAGE | win32gui.NIF_TIP
nid = (self.hwnd, 0, flags, win32con.WM_USER+20, hicon, "Python Demo")
try:
win32gui.Shell_NotifyIcon(win32gui.NIM_ADD, nid)
except win32gui.error:
# This is common when windows is starting, and this code is hit
# before the taskbar has been created.
print "Failed to add the taskbar icon - is explorer running?"
# but keep running anyway - when explorer starts, we get the
# TaskbarCreated message.
def OnRestart(self, hwnd, msg, wparam, lparam):
print "In onrestart"
self._DoCreateIcons()
def OnDestroy(self, hwnd, msg, wparam, lparam):
nid = (self.hwnd, 0)
win32gui.Shell_NotifyIcon(win32gui.NIM_DELETE, nid)
win32gui.PostQuitMessage(0) # Terminate the app.
def OnTaskbarNotify(self, hwnd, msg, wparam, lparam):
if lparam==win32con.WM_LBUTTONUP:
print "You clicked me."
print win32gui.GetWindowText(hwnd)
print ".." + win32gui.GetWindowText(win32gui.GetForegroundWindow())
self.screen_shoot()
elif lparam==win32con.WM_LBUTTONDBLCLK:
print "You double-clicked me - goodbye"
win32gui.DestroyWindow(self.hwnd)
elif lparam==win32con.WM_RBUTTONUP:
print "You right clicked me."
return 1
def screen_shot(self):
wndh = win32gui.GetForegroundWindow()
if "Notepad" in win32gui.GetWindowText(wndh):
print "Inside if"
hwndDC = win32gui.GetWindowDC(wndh)
mfcDC = win32ui.CreateDCFromHandle(hwndDC)
saveDC = mfcDC.CreateCompatibleDC()
saveBitMap = win32ui.CreateBitmap()
left, top, right, bot = win32gui.GetWindowRect(wndh)
w = right - left
h = bot - top
saveBitMap.CreateCompatibleBitmap(mfcDC, w, h)
saveDC.SelectObject(saveBitMap)
saveDC.BitBlt((0, 0), (w, h), mfcDC, (0, 0), win32con.SRCCOPY)
bmpinfo = saveBitMap.GetInfo()
bmpstr = saveBitMap.GetBitmapBits(True)
im = Image.frombuffer('RGB', (bmpinfo['bmWidth'],
bmpinfo['bmHeight']),
bmpstr, 'raw', 'BGRX', 0, 1)
win32gui.DeleteObject(saveBitMap.GetHandle())
saveDC.DeleteDC()
mfcDC.DeleteDC()
win32gui.ReleaseDC(wndh, hwndDC)
im.save("c:screenshot" + str(int(time.time())) + ".png")
def OnCommand(self, hwnd, msg, wparam, lparam):
id = win32api.LOWORD(wparam)
if id == 1023:
import win32gui_dialog
win32gui_dialog.DemoModal()
elif id == 1024:
print "Hello"
elif id == 1025:
print "Goodbye"
win32gui.DestroyWindow(self.hwnd)
else:
print "Unknown command -", id
def main():
w=MainWindow()
win32gui.PumpMessages()
if __name__=='__main__':
main()
在上面的代码中，控件从未进入screen_shot函数中的if条件。如何使该程序正常工作？当作为普通应用程序运行时，相同的屏幕截图逻辑工作正常。
回答自己的问题。。。刚刚实现的任务栏也是另一个"窗口"&单击系统任务栏图标后，焦点转移到任务窗口。这就是被报告为前景窗口&获取此窗口的窗口文本为空字符串。我通过稍微修改我的程序来验证这一点。在MainWindow类init函数中，win32gui.Shell_NotifyIcon(win32gui.NIM_ADD, nid)图标init调用后添加了以下代码来验证它
while True:
time.sleep(0.1)
wndh = win32gui.GetForegroundWindow()
print "windowndh" + str(wndh)
if "Notepad" in win32gui.GetWindowText(wndh):
# Take screen shot
print "Inside if"