Clipboard error -2147221040: OpenClipboard Failed

wxPython Users
#1

trying to get this to work, using Mike Driscoll script

import wx

########################################################################
class ClipboardPanel(wx.Panel):
    """"""

    #----------------------------------------------------------------------
    def __init__(self, parent):
        """Constructor"""
        wx.Panel.__init__(self, parent)
        
        lbl = wx.StaticText(self, label="Enter text to copy to clipboard:")
        self.text = wx.TextCtrl(self, style=wx.TE_MULTILINE)
        copyBtn = wx.Button(self, label="Copy")
        copyBtn.Bind(wx.EVT_BUTTON, self.onCopy)
        copyFlushBtn = wx.Button(self, label="Copy and Flush")
        copyFlushBtn.Bind(wx.EVT_BUTTON, self.onCopyAndFlush)
        
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(lbl, 0, wx.ALL, 5)
        sizer.Add(self.text, 1, wx.EXPAND)
        sizer.Add(copyBtn, 0, wx.ALL|wx.CENTER, 5)
        sizer.Add(copyFlushBtn, 0, wx.ALL|wx.CENTER, 5)
        self.SetSizer(sizer)
        
    #----------------------------------------------------------------------
    def onCopy(self, event):
        """"""
        self.dataObj = wx.TextDataObject()
        self.dataObj.SetText(self.text.GetValue())
        if wx.TheClipboard.Open():
            wx.TheClipboard.SetData(self.dataObj)
            wx.TheClipboard.Close()
        else:
            wx.MessageBox("Unable to open the clipboard", "Error")
            
    #----------------------------------------------------------------------
    def onCopyAndFlush(self, event):
        """"""
        self.dataObj = wx.TextDataObject()
        self.dataObj.SetText(self.text.GetValue())
        if wx.TheClipboard.Open():
            wx.TheClipboard.SetData(self.dataObj)
            wx.TheClipboard.Flush()
        else:
            wx.MessageBox("Unable to open the clipboard", "Error")
            
        self.GetParent().Close()

########################################################################
class ClipboardFrame(wx.Frame):
    """"""

    #----------------------------------------------------------------------
    def __init__(self):
        """Constructor"""
        wx.Frame.__init__(self, None, title="Clipboard Tutorial")
        panel = ClipboardPanel(self)
        self.Show()
    
    
if __name__ == "__main__":
    app = wx.App(False)
    frame = ClipboardFrame()
    app.MainLoop()

periodically I get an error - Failed to put data on the clipboard (error -2147221040: OpenClipboard Failed)

if I paste into note pad after receiving the error
[Window Title]
Shop Error

[Content]
Failed to put data on the clipboard (error -2147221040: OpenClipboard Failed)

[OK]

This of course could be a windows thing,
I’m using win10, python 3.6.8 wx ‘4.1.0 msw (phoenix) wxWidgets 3.1.4’

Thanks in advance.

#2

I tried your code and I don’t see issues (Windows, Python 3.6.4 64 bit,
wxPython 4.1.0).
Are you sure that you don’t have any other program working with the
clipboard?

E.g. if I insert a delay between TheClipboard.Open() and Close() and run
two instances then I can trigger the issue.

Regards,

Dietmar

1 Like
#3

Thanks for your reply, this is an app that runs pretty much all day. The problem seems random, only 1 instance of the app needs to be running. We’re trying to copy data from cells in a grid, one by one and paste into a web site form. Putting try/except doesn’t catch the error, I’ve put a check in which seems to help a bit, but still seems random and happens on all 4 computers on site.
if wx.TheClipboard.IsOpened():
wx.TheClipboard.Close()

#4

Ok, I see. If I call onCopy automatically often enough, then I see the error as well.
Just wait for a small time and try again. After all, TheClipboard.Open() is the same as e.g. a threading.Lock to make sure only one program uses the exclusive resource.
I would not worry about that. There may be Windows processes checking the clipboard.

I have just tried with win32clipboard and I see the problem there as well.

(Be aware that win32clipboard.OpenClipboard wil raise pywintypes.error: (5, 'OpenClipboard', 'Access denied')

    def onCopy(self, event=None):
        text = self.text.GetValue()
        window_handle = self.GetHandle()
        win32clipboard.OpenClipboard(window_handle)  # will raise an error if it fails
        try:
            win32clipboard.EmptyClipboard()
            if sys.version_info.major==2:
                is_unicode = isinstance(text, str)
            else:
                is_unicode = True
            if is_unicode:
                win32clipboard.SetClipboardData(win32clipboard.CF_UNICODETEXT, text)
            else:
                win32clipboard.SetClipboardText(text)
        finally:
            win32clipboard.CloseClipboard()
1 Like
#5

Thanks a million for your help, if I could catch the error I could display my own message, I think the error message we’re seeing is from windows.

#6

Oh, yes, you’re right. wx.TheClipboard.Open() should not trigger an error dialog.
As workaround you may switch to the win32clipboard code.

#7

changed to win32clipboard as suggested and has been running for some days now without a single error, again, thanks for your help.