如何在长印刷机上用tkinter添加数字？

Question

在tkinter GUI中，我有一些数字，当按下长键时，它应该继续与前一个数字相加。按键松开后停止。我已经尝试了greenbutton.bind('<ButtonPress-1>', start_motor)不同的事件，我无法解决。

Answer 1

没有内置的方法可以做到这一点，你需要手动监控按钮的按下和释放。这将是一个使用Button子类的好地方。如下所示：

import tkinter as tk

class LongPressButton(tk.Button):
    def __init__(self, master=None, command=None, repeat_time=250, **kwargs):
        super().__init__(master, **kwargs)
        self.command = command
        self.repeat_time = repeat_time
        self.command_trigger = ' '
        self.bind('<ButtonPress-1>', self.on_press)
        self.bind('<ButtonRelease-1>', self.on_release)

    def on_press(self, event=None):
        if self.command is not None:
            self.command()
        self.command_trigger = self.after(self.repeat_time, self.on_press)

    def on_release(self, event=None):
        self.after_cancel(self.command_trigger)

### TEST / DEMO:
def tick_func():
    print("tick")

root = tk.Tk()
root.geometry('200x200')
greenbutton = LongPressButton(root, text='click and hold me!!', bg='green', command=tick_func)
greenbutton.pack()
bluebutton = LongPressButton(root, text="I'm faster!!", bg='light blue', command=tick_func, repeat_time=80)
bluebutton.pack()
root.mainloop()