On 03/12/2018 08:58, huey.y.ji...@gmail.com wrote: > Hi Folks, > > I need to run an infinite loop on a Menu button, like this: > > from Tkinter import * > > def run_job(): > i = 0 > while 1: > i = i + 1 > if i > 100: > break > ....... > > root = Tk() > menu = Menu(root) > root.config(menu=menu) > filemenu = Menu(menu) > menu.add_cascade(label="Jobs", menu=filemenu) > filemenu.add_command(label="Run", command=run_job) > mainloop() > > > In fact, the def run_job has more things to do. But, it is an infinite loop > in essence. It works. However, when the def run_job is running, the menu will > be hang there. I have no way to stop it. Even if I raise it with > Key-Interupt, the thing was the same: the infinite loop cannot be stopped > nicely. The only way was to wait until the Python interpreter notice the > problem, and popped out an error message, then I can kill the running program.
Basic rule of thumb for GUI programming: never block the main (GUI) thread, i.e. never run any long-running task in the main thread. If you want to start a long-running task from a GUI event, start a worker thread; from there, you could then perhaps update a progress bar in your loop. If you want to be able to stop the task from the GUI, you'll want something like a "stop the task ASAP please" flag/variable set by the stop button that the loop periodically checks. > > Can anybody tell me how to handle this? I wish when variable i reached 100, > the run_job will be end, and the Menu "Run" will be free. > > Thanks in advance. > -- https://mail.python.org/mailman/listinfo/python-list
