将绑定事件添加到使用循环创建的输入字段中

Question

The main aim here is too bind events to entry fields which are created dynamically using loops and then fetch the values from those fields, how ever i am having issues here to create a function that grabs the text from the entry field as soon as the user starts typing in the box.

from tkinter import Tk, LEFT, BOTH, StringVar
from tkinter.ttk import Entry, Frame
import functools


class Example(Frame):
    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent
        self.initUI()

    def initUI(self):
        self.parent.title("Entry")
        self.pack(fill=BOTH, expand=1)
        self.contents = []
        self.ent = []
        for i in range(0,5):
            self.contents.append(StringVar())

        # give the StringVar a default value
        for i in range(0,5):
            self.entry = Entry(self)
            self.entry.grid(row=0,column=i)
            self.entry["textvariable"] = self.contents[i]
            self.entry.bind('<KeyRelease>', self.on_changed)
            self.ent.append(self.entry)

    def on_changed(self, event):
        print('contents: {}'.format(self.contents.get()))
        return True
def main():
    root = Tk()
    ex = Example(root)
    root.geometry("800x400")
    root.mainloop()


if __name__ == '__main__':
    main()

Answer 1

When you use bind , the event object that is passed to the callback includes a reference to the widget, which you can use to get the value of the entry.

Example

def on_changed(self, event):
    entry = event.widget
    print('contents: {}'.format(entry.get()))
    return True