Question

我正在尝试更改tkinter画布小部件上的对象数组的状态，但是需要等待一段时间才能使更改生效。当定义不带参数的change_color（）函数时，行为是预期的，因此我首先看到画布和对象处于初始状态，然后是延迟，然后是对象处于最终状态。当我在函数定义中添加一个参数，然后调用它传递一个参数以选择要更改的对象时，最终结果可以，但是在画布上没有显示初始状态或延迟。是否可以将参数传递给从Tkinter调用的函数？

# LED simulation using tkinter canvas widget

from tkinter import *

root = Tk()
root.geometry('640x480')
root.title('LED Simulation')

canvas = Canvas(width=640, height=480, bg='black')
canvas.pack()

# create LED objects on the canvas in the OFF state (dark red)
d7 = canvas.create_oval(50, 50, 75, 75, fill='dark red')
d6 = canvas.create_oval(100, 50, 125, 75, fill='dark red')
d5 = canvas.create_oval(150, 50, 175, 75, fill='dark red')
d4 = canvas.create_oval(200, 50, 225, 75, fill='dark red')
d3 = canvas.create_oval(250, 50, 275, 75, fill='dark red')
d2 = canvas.create_oval(300, 50, 325, 75, fill='dark red')
d1 = canvas.create_oval(350, 50, 375, 75, fill='dark red')
d0 = canvas.create_oval(400, 50, 425, 75, fill='dark red')

# changes the state of an LED from OFF to ON (red)
def change_color(led):
    canvas.itemconfig(led, fill='red')

# wait for 1 sec, then change state to ON
root.after(1000, change_color(d3)) 

root.mainloop()

Answer 1

如亨利先生所说，您可以使用lambda：

root.after(1000, lambda: change_color(d3))

在Tkinter中将参数传递给函数会禁止after（）方法操作

1 个答案: