Using Tkinter To Watch For Clipboard,what's Wrong With My Code?

Some description about the code: This is part of my program and I only put the related lines here What I hope these code could do,is to watch for my clipboard.If I copy 'http:xxx'

Solution 1:

I think multithreading isn't the best approach for your situation and after may be enough. Instead of a busy waiting loop, you can call tk.after with a lower timeout. Then you just need to move the logic of watch_clipboard to your class, so you don't have to worry about the communication between the threads.

classGUI:
    def__init__(self):
        self.tk = Tk()
        self.tk.resizable(0, 0)
        self.tk.title('watch clipboard')
        self.last_content = ''
        self.tk.after(100, self.watch_clipboard)
        self.tk.mainloop()
    defwatch_clipboard(self):
        try:
            content = self.tk.clipboard_get()
            if content != self.last_content and content.startswith('http:'):
                self.last_content = content
                self.tk.clipboard_clear()
                messagebox.askokcancel('', 'add this in?', default='ok')
        except TclError:
            pass
        self.tk.after(100, self.watch_clipboard)

Solution 2:

@laike9m The error with your code is that os.pipe is used. Os.read() is a blocking function that will receive os.read() blocking once clipboard_confirm is run. Causes the UI to get stuck. This bug has nothing to do with after and multithreading.

Solution 3:

There's a good chance the problem is related to using threads -- calling Tkinter functions from anywhere other than the main thread can cause problems.

Is there a reason you're using a thread rather than takingbadvantage of the built-in infinite loop (the event loop)? I would advise making use of after to check the keyboard every second or so.