UpdateLayeredWindow in pywin32

[livibetter]

Hi!

I am trying to making an On-Screen Display, which is implemented by
wx.Frame.
Basically I created a wx.Frame with style like

super(OSDBase, self).__init__( parent, id, title,
style = wx.STAY_ON_TOP |
wx.FRAME_NO_TAS KBAR |
wx.TRANSPARENT_ WINDOW |
wx.NO_BORDER)
self.SetTranspa rent(128)

But if I try to draw an image with alpha channel(like PNG format), I
always get
a background behind this image. But I don't want the background.

Then I read this article, http://www.codeproject.com/csharp/OSDwindow.asp
The demo program is written in C#. I understand that I need to use
UpdateLayeredWi ndow to update visual content of a layered window.

But I always got an error:

Traceback (most recent call last):
File "osd_post.p y", line 60, in <module>
osd.Update()
File "osd_post.p y", line 56, in Update
2)
pywintypes.erro r: (87, 'UpdateLayeredW indow', 'The parameter is
incorrect.')

I am not sure did I use UpdateLayeredWi ndow correctly.

Any help would be appreciated.


My Python is 2.5, pywin32 is 210, wxPython is 2.8.1

UpdateLayeredWi ndow Function Help from MSDN:
http://msdn2.microsoft.com/en-us/library/ms633556.aspx

UpdateLayeredWi ndow Function Help from pywin32:

http://aspn.activestate.com/ASPN/docs/ActivePython/2.4/pywin32/win32gui__UpdateLayeredWindow_meth.html

My source code:

"""pyitctrl - OSD"""
# Created Date : 2007/03/14
# Author: livibetter

import wx, winxpgui, win32con

class OSDBase(wx.Fram e):
def __init__(self, parent, id, title):
super(OSDBase, self).__init__( parent, id, title,
style = wx.STAY_ON_TOP |
wx.FRAME_NO_TAS KBAR |
wx.TRANSPARENT_ WINDOW |
wx.NO_BORDER)
self.SetTranspa rent(128)

print hex(winxpgui.Ge tWindowLong(sel f.GetHandle(),
win32con.GWL_EX STYLE))
print winxpgui.GetLay eredWindowAttri butes(self.GetH andle())

self.img = wx.Image("icon. png")
self.bmp = self.img.Conver tToBitmap()
w, h = self.bmp.GetWid th(), self.bmp.GetHei ght()
self.SetClientS ize( (w, h) )

def Update(self):
print "Update"

screenDC = winxpgui.GetDC( winxpgui.GetDes ktopWindow())
print screenDC
cScreenDC = winxpgui.Create CompatibleDC(0)
print cScreenDC

(w, h) = self.GetSizeTup le()
bmp = wx.EmptyBitmap( w, h)
tmpDC = wx.MemoryDC()
tmpDC.SelectObj ect(bmp)
tmpDC.SetBackgr ound(wx.Brush(" BLACK"))
tmpDC.Clear()
tmpDC.DrawBitma p(self.bmp,0,0, True)
tmpDC.Destroy()
del tmpDC

winxpgui.Select Object(cScreenD C, bmp.GetHandle() )

winxpgui.Update LayeredWindow(s elf.GetHandle() ,
screenDC,
self.GetPositio nTuple(),
self.GetSizeTup le(),
cScreenDC,
(0,0),
0,
(0,0,128,1),
win32con.ULW_AL PHA)

app = wx.App(False)
osd = OSDBase(None, wx.ID_ANY, 'OSD Frame')
osd.Update()
osd.Show()

app.MainLoop()

[livibetter]

Re: UpdateLayeredWi ndow in pywin32

I have found the cause

"Please note that after SetLayeredWindo wAttributes has been called,
subsequent UpdateLayeredWi ndow calls will fail until the layering
style bit is cleared and set again."
from http://msdn2.microsoft.com/en-us/lib...9.aspx#layered

But I still can't use winxpgui.Update LayeredWindow, Now I am using
ctypes to enable calling UpdateLayeredWi ndow, and this works.