Question

每当按下向上或向下箭头键时，我都试图使输入值增加或减少。要做到这一点，我需要首先找到关注的条目，并且我试图这样做＆＃34; .focus_get（）＆＃34;。问题是我无法弄清楚它的工作原理或返回方式。它为每个条目返回1个唯一编号，例如：＆＃34; .45191744＆＃34;但是每次运行程序时这个数字都会改变。运行代码时，以下数字表示最近5次尝试。＆＃34; 0.50518728＆＃34; ＆＃34; 0.53009096＆＃34; ＆＃34; 0.55889592＆＃34; ＆＃34; 0.51891896＆＃34;

如何获得焦点条目的变量名称？

这是我的代码：

def get_focus1(event):
    print("return: event.widget is", event.widget)
    print("focus is:", window2.focus_get())
    print(window2.focus_get())
    print(help(window2.Entry))

window2 = Tk()

eyear1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for year
eyear1.insert(10, defaultYear)
eyear1.grid(row=1, column=1)

emonth1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for Month
emonth1.insert(10, defaultMonth)
emonth1.grid(row=1, column=2)

eday1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for day
eday1.insert(10, defaultDay)
eday1.grid(row=1, column=3)

window2.bind('<Left>', get_focus1)

mainloop()

Answer 1

focus_get返回实际对象。你想做什么，~~假设你没有充分使用textvariable~~ （参见Bryan的评论），是清除文本并重新写入新值（显然要做一些验证）。你最终得到的是这样的：

from tkinter import *

def up(event):
    # warning, exceptions can happen
    old = int(event.widget.get()) # this gives back the actual object!
    event.widget.delete(0, END) # delete existing text
    event.widget.insert(10, old + 1) # put new text in

def down(event):
    # warning, exceptions can happen
    old = int(event.widget.get()) # this gives back the actual object!
    event.widget.delete(0, END) # delete existing text
    event.widget.insert(10, old - 1) # put new text in

window2 = Tk()

eyear1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for year
eyear1.insert(10, 2015)
eyear1.grid(row=1, column=1)

emonth1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for Month
emonth1.insert(10, 1)
emonth1.grid(row=1, column=2)

eday1 = Entry(window2, width=4, font=("Helvetica", 16)) #  Entry for day
eday1.insert(10, 10)
eday1.grid(row=1, column=3)

# bind both keys to corresponding event handlers
window2.bind('<Up>', up)
window2.bind('<Down>', down)
mainloop()

Answer 2

请记住，当您调用print时，您将获得对象的表示，而不一定是对象本身。要向您展示正在进行的操作，请将其添加到get_focus1功能：

print("focus object class:", window2.focus_get().__class__)

您应该看到它确实返回了对Entry小部件的引用，这意味着您可以调用该对象上的所有常规方法。

Python获得专注的条目名称

2 个答案: