删除和更改 tkinter 事件绑定 [英] Deleting and changing a tkinter event binding

问题描述

如何停止处理事件或切换为其调用的函数?

How do i stop an event from being processed or switch what function is called for it?

修订代码:

from Tkinter import *

class GUI:
    def __init__(self,root):
        Window = Frame(root)
        self.DrawArea = Canvas(Window)
        self.DrawArea.pack()
        Window.pack()

        self.DrawArea.bind("<Button 1>",self.starttracking)

    def updatetracking(self,event):
        print event.x,event.y

    def finishtracking(self,event):
        self.DrawArea.bind("<Button 1>",self.starttracking)
        self.DrawArea.unbind("<Motion>")

    def starttracking(self,event):
        print event.x,event.y
        self.DrawArea.bind("<Motion>",self.updatetracking)
        self.DrawArea.bind("<Button 1>",self.finishtracking)



if __name__ == '__main__':
    root = Tk()
    App = GUI(root)
    root.mainloop()

推荐答案

您只需再次使用该事件的新函数调用 bind() 即可.由于您没有使用第三个参数，add，在 bind() 中，这只会覆盖已经存在的任何内容.默认情况下，此参数为 '' 但它也接受 "+"，这将向该事件已触发的回调添加回调.

You can simply just call bind() again with the new function for the event. Since you are not making use of the third parameter, add, in bind() this will just overwrite whatever is already there. By default this parameter is '' but it also accepts "+", which will add a callback to the callbacks already triggered by that event.

如果您开始使用该可选参数，则您将需要使用 unbind() 函数来删除单个回调.当您调用 bind() 时，会返回一个 funcid.您可以将此 funcid 作为第二个参数传递给 unbind().

If you start using that optional argument however you will need to use the unbind() function to remove individual callbacks. When you call bind() a funcid is returned. You can pass this funcid as the second parameter to unbind().

示例:

self.btn_funcid = self.DrawArea.bind("<Button 1>", self.my_button_callback, "+")

# Then some time later, to remove just the 'my_button_callback':
self.DrawArea.unbind("<Button 1>", self.btn_funcid)

# But if you want to remove all of the callbacks for the event:
self.DrawArea.unbind("<Button 1>")

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