tkinter gpio 状态问题.. 我怎样才能让它更新标签以显示最新状态

Question

这可以在启动时显示标签，它显示 gpio 9 的原始状态，但是当您单击按钮时，它不会更改标签文本。我希望它读取 gpio 的实际状态，而不是单击按钮的事实。任何帮助，将不胜感激。#tktrial#!/usr/bin/env python3import RPi.GPIO as GPIOimport timetime.sleep(1)import tkinter as tkGPIO.setwarnings(False)GPIO.setmode(GPIO.BCM)#setup output pins for relay controlGPIO.setup(9, GPIO.OUT)   #power head 1 ch 4 relay#setup tkinterroot=tk.Tk()root.title("trial Aquarium")root.geometry("800x550")root.configure(bg="lightblue")photo1 = tk.PhotoImage(file="fish.gif") #defines a photo and gives the file namelabel1 = tk.Label(image=photo1)#puts label in the window in this case not text file must be in program folderlabel1.grid(row=10, column=0, columnspan=12) #says how to place the label#setup fontsftlab= 'Verdana', 13, 'bold'ftb= 'Verdana', 11, 'bold'#define functions for button     def pwrhd2on():    GPIO.output(9, GPIO.HIGH)def pwrhd2off():    GPIO.output(9, GPIO.LOW)state = GPIO.input(9)if state:    rt2=('On')else:    rt2=('Off')#setup exit buttonExitbutton= tk.Button(root, text="Exit", font=(ftb), width=6, bg="red", fg="white", command=root.destroy)Exitbutton.place(x=700, y=240)#setup powerhead 2 buttons and labellabelpwrhd2= tk.Label(root, text=("POWER HEAD  2"), font=(ftlab), bg="orange", fg="black")labelpwrhd2.place(x=0, y=496)butpwrhd2= tk.Button(root, text=("PUMP  ON"), font=(ftb), command=pwrhd2on)butpwrhd2.place(x=180, y=492)butpwrhd2= tk.Button(root, text=("PUMP OFF"), font=(ftb), command=pwrhd2off)butpwrhd2.place(x= 300, y= 492)labelpwrhd2gpio= tk.Label(root, text=("GPIO          9"), font=(ftlab), bg="black", fg="white")labelpwrhd2gpio.place(x= 670, y=496)labelpwrhd2state= tk.Label(root, text=rt2, font=(ftlab), bg="green", fg="black")labelpwrhd2state.place(x=570, y=496)root.mainloop()

Answer 1

在定义函数之前创建标签。利用

def pwrhd2on():

    GPIO.output(9, GPIO.HIGH)

    labelpwrhd2state.configure(text='GPIO 9 On')

def pwrhd2off():

    GPIO.output(9, GPIO.LOW)

    labelpwrhd2state.configure(text='GPIO 9 Off')

消除

state = GPIO.input(9)

if state:

    rt2=('On')

else:

    rt2=('Off')

text=rt2, 希望这会有所帮助！