我一直在编写一些我一直在写的程序的问题，并希望得到一些帮助或输入。对于某些背景，我使用Python 2.7和wxPython来做一个流媒体网络摄像头客户端。客户端从自己的线程中获取服务器中的图像，并将它们放入队列中。然后，GUI线程从队列中获取这些图像并将它们转换为wxBitmap对象。这种情况每0.5秒发生一次，效果很好。我能够将wxBitmap对象保存为文件，因此我知道一切正常。
我遇到的问题实际上是让wxBitmap对象显示在我的GUI上。我似乎唯一可以做GUI的工作是显示一个灰色矩形，其中应该是网络摄像头图像。
以下是我要刷新屏幕时调用的onPaint()：
def onPaint(self,e):
## this is the function that actually draws and redraws the window
## to be displayed. I think it is something similar to blit()
## in other graphical display frameworks
print "in onPaint"
## create the device context object (graphics painter)
dc = wx.PaintDC(self)
dc.BeginDrawing()
## draw the bitmap to the screen
dc.DrawBitmap(self.imageBit,0,0,True)
dc.EndDrawing()
## test code.
## the following works and updates, which means that
## everything is being converted properly and updated.
## not sure why the dc won't paint it to the window.
self.imageBit.SaveFile("bit.bmp", wx.BITMAP_TYPE_BMP)
简单地说，我不知道为什么它不起作用。从我的研究中我发现，因为我在Windows机器上，我需要BeginDrawing()和EndDrawing()函数，所以我添加了它们。仍然无法正常工作。没有错误或异常被抛出。
可能有助于解决此问题的其他问题：
wxFrame个对象。也许wxPaintDC需要在另一种类型的容器中运行才能工作？实际上，也许我的__init__函数存在问题。我正确地设置了吗？
class viewWindow(wx.Frame):
imgSizer = (480,360)
def __init__(self, *args, **kw):
## this is called when an instance of this class is created
super(viewWindow,self).__init__(*args,**kw)
## here is where the actual stuff inside the frame is set up.
self.pnl = wx.Panel(self)
## create a button that opens up a Connection Window
#test = wx.Button(self.pnl, label='Connection Settings')
## test.Bind(wx.EVT_BUTTON, self.openConnectionWindow)
## create the wxImage for the web cam pic
self.image = wx.EmptyImage(self.imgSizer[0],self.imgSizer[1])
## create the wxBitmap so that the wxImage can be displayed
self.imageBit = wx.BitmapFromImage(self.image)
## create a timer that will update the window based of frame rate
self.timex = wx.Timer(self, wx.ID_OK)
self.timex.Start(500)
self.Bind(wx.EVT_TIMER, self.redraw, self.timex)
## need to do the following in order to display images in wxPython:
self.Bind(wx.EVT_PAINT, self.onPaint)
self.SetSize(self.imgSizer)
self.SetTitle('View Window')
self.Show()
无论如何，提前感谢您的帮助。
编辑：我通过删除行self.pnl = wx.Panel(self)意外地解决了问题。
显然它渲染得很好，但位图位于面板下方。也许？我不太确定。我是整个wxPython的新手。
答案 0 :(得分：1)
这似乎也是wxPython演示所做的：dc.DrawBitmap。它适用于Windows！至少，这就是他们在AlphaDrawing演示中所做的事情。在DrawImage演示中，他们使用dc.Blit（）。你可以尝试一下。
然而，我想知道你是不是像我对photo viewer那样做了。我不使用DC来绘制，而只是使用我更新的wx.StaticBitmap。
答案 1 :(得分：1)
此代码有效。它每次都显示图像。但它确实倾向于“闪烁”。所以我可能还有一种更好的方法，我不知道。
class viewWindow(wx.Frame):
imgSizer = (480,360)
def __init__(self, parent, title="View Window"):
super(viewWindow,self).__init__(parent)
## create the menu and its sub trees
menubar = wx.MenuBar()
filemenu = wx.Menu()
menubar.Append(filemenu, 'File')
self.fitem = filemenu.Append(wx.ID_ANY, 'Open Connection Window')
self.Bind(wx.EVT_MENU, self.openConnectionWindow, self.fitem)
self.SetMenuBar(menubar)
## here is where the actual stuff inside the frame is set up.
self.pnl = wx.Panel(self)
self.vbox = wx.BoxSizer(wx.VERTICAL)
## create the wxImage for the web cam pic
self.image = wx.EmptyImage(self.imgSizer[0],self.imgSizer[1])
## create the wxBitmap so that the wxImage can be displayed
self.imageBit = wx.BitmapFromImage(self.image)
self.staticBit = wx.StaticBitmap(self.pnl,wx.ID_ANY, self.imageBit)
## add the staticBit to the sizer so it is rendered properly on resizes and such
## note: not actually needed to get the image to display, but reccommended for ease
## of layout
self.vbox.Add(self.staticBit)
## register the sizer with the panel so the panel knows to use it.
self.pnl.SetSizer(self.vbox)
## create a timer that will update the window based on frame rate
self.timex = wx.Timer(self, wx.ID_OK)
self.timex.Start(1000/framerate)
self.Bind(wx.EVT_TIMER, self.redraw, self.timex)
## set the size of the frame itself when it is first opened
self.SetSize(self.imgSizer)
self.Show()
def openConnectionWindow(self, e):
## this will open a new connection window
connect = connectionWindow(None)
def redraw(self,e):
## this function updates the frame with the latest web cam image that has been
## retrieved by the client thread from the server.
## get the newest image in the queue
if not imgQ.empty():
picz = imgQ.get()
## convert the image from a string to something usable (wxImage)
self.image.SetData(picz)
## from wxImage to wxBitmap
self.imageBit = wx.BitmapFromImage(self.image)
self.staticBit = wx.StaticBitmap(self.pnl,wx.ID_ANY, self.imageBit)
## refresh the frame
self.Refresh()
答案 2 :(得分：0)
几个小时后，我研究了一个不同的问题，我发现了这个问题：
How to detect motion between two PIL images? (wxPython webcam integration example included)
其中的示例代码效果很好。