Python Tkinter IntVar 未更新 [英] Python Tkinter IntVar Not Updating

问题描述

我有两个函数是 Python 3.4.1 Tkinter GUI 的一部分.

I have two functions that are part of a Python 3.4.1 Tkinter GUI.

def jumpto():
    global jump
    jump = Tk()
    jump.wm_title("Jump")
    jump.focus_force()
    label = Label(jump, text = "Enter digit to jump:").pack()
    global jumptext
    jumptext = IntVar()
    jumpentry = Entry(jump, textvariable = jumptext)
    jumpentry.pack()
    jump.bind("<Return>", close)

def close(self):
    global jumptext
    global jump
    print(jumptext.get())
    while digit < jumptext.get(): #digit is an integer that increases in the unrelated area below
        #Do something completely unrelated
    jump.destroy()

jButton = Button(master, text = "JUMP", command = jumpto).pack() #master is the main Tk window

但是，当我运行代码时，close 中的 jumptext.get() 仍然为 0，尽管在使用 jumpentry 创建的输入框中输入了一些内容.有什么方法可以使输入的信息实际更新到 jumptext.get()?

However, when I run the code, jumptext.get() within close remains 0, despite something being typed in to the entry box created with jumpentry. Any way to make it so that the information entered actually updates to jumptext.get()?

另外，如果有人能向我解释为什么必须在 close 中输入 self，那将是一个奖励.

Also, if anyone could explain to me why self must be entered within close, that would be a bonus.

提前致谢！

推荐答案

问题是您正在创建 Tk() 的两个实例，这会导致奇怪的行为.jump 窗口应该是 Toplevel窗口，如果您希望在 Tk() 窗口旁边有另一个窗口，则使用该窗口.

The thing is that you're making two instances of Tk(), which leads to strange behavior. The jump window should be a Toplevel window, which is the window to use if you want another window next to your Tk() window.

close 需要接受一个参数，因为它被一个 bind 调用，它总是传递一个 event 对象，其中包含有关触发 close 函数的事件的各种信息(例如鼠标位置和键用于触发事件).所以称它为 event 而不是 self 实际上会更正确.self 是在包含类属性的类中使用的变量.

close needs to accept an argument because it is called by a bind which always passes an event object which contains all kinds of information about the event that triggered the close function (things like mouse position and the key that was used to trigger the event). So calling it event instead of self would actually be more correct. self is a variable used in classes which contains class attributes.

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