用tkinter显示最新的输入信号

Question

python 2.7

我用树莓皮来监控一些数字输入信号，作为一个业余项目。我希望有一个大的显示，显示累积的值，并更新他们的全局变量，将跟踪输入信号。现在，我将在面包板上使用按钮，所以我尝试使用一个保持变量来防止计数器在每一个周期中递增。我对Python非常陌生，因为我确信这是显而易见的，所以如果可能的话，请保持简单。我调用一个输入PE_MATTRESSES、另一个PE_COMBINED和另一个RESET，希望显示从PE_COMBINED中减去PE_MATTRESSES的第三个值。当然，RESET会把所有的东西都归零。

不过，我的伪代码是：

• 建立I/O和全局变量
• 创建GUI
• 而1 -看看I/O -更新全球变量 -更新标签以显示标签 --循环

我的代码如下：

import Tkinter as tk
import tkFont
import time
import RPi.GPIO as GPIO


GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(21, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(22, GPIO.IN, pull_up_down=GPIO.PUD_UP)


PE_MATTRESS = GPIO.input(17)
PE_MATTRESS_LATCH = 0
PE_MATTRESS_ACCUMULATOR = 0
PE_COMBINED = GPIO.input(21)
PE_COMBINED_LATCH = 0
PE_COMBINED_ACCUMULATOR = 0
BOXSPRING_ACCUMULATOR = 0
BOXSPRING_ACCUMULATOR = PE_COMBINED_ACCUMULATOR - PE_MATTRESS_ACCUMULATOR 
RESET = GPIO.input(22)



class App:
    def __init__(self):
        root=tk.Tk()
        # create a custom font
        self.customFont = tkFont.Font(family="Helvetica", size=117)


        # create widgets 

        label1 = tk.Label(root, text="MATTRESSES: %s" % PE_MATTRESS_ACCUMULATOR , font=self.customFont)
        label1.pack()

        spacer1 = tk.Label(root, text="", font=self.customFont)
        spacer1.pack()

        Quit = tk.Button(root, text="QUIT", command=quit)
        Increment = tk.Button(root, text="Test", command=Inc)
        Quit.pack()
        Increment.pack()


        label2 = tk.Label(root, text="BOXSPRINGS: %s" % BOXSPRING_ACCUMULATOR, font=self.customFont)
        label2.pack()

        spacer2 = tk.Label(root, text="", font=self.customFont)
        spacer2.pack()


        label3 = tk.Label(root, text="      COMBINED: %s" % PE_COMBINED_ACCUMULATOR, font=self.customFont)
        label3.pack()



        root.geometry('1800x1000+0+0')
        root.after(10,Inputs)

        root.mainloop()

    def Inc():

        PE_MATTRESS_ACCUMULATOR = PE_MATTRESS_ACCUMULATOR + 1
    label1.setText("MATTRESSES: %s" % PE_MATTRESS_ACCUMULATOR)
    label2.setText("BOXSPRINGS: %s" % BOXSPRING_ACCUMULATOR)
    label3.setText("      COMBINED: %s" % PE_COMBINED_ACCUMULATOR)

        root.update_idletasks()


    def Inputs():

        if PE_MATTRESS == True and PE_MATTRESS_LATCH == False:
            PE_MATTRESS_ACCUMULATOR = PE_MATTRESS_ACCUMULATOR + 1
            PE_MATTRESS_LATCH = True


        elif PE_MATTRESS == False and PE_MATTRESS_LATCH == True:
            PE_MATTRESS_LATCH = False

        elif PE_COMBINED == True and PE_COMBINED_LATCH == False:
            PE_COMBINED_ACCUMULATOR = PE_COMBINED_ACCUMULATOR + 1
            PE_COMBINED_LATCH = True

        elif PE_COMBINED == False and PE_COMBINED_LATCH == True:
            PE_COMBINED_LATCH = False

        elif RESET == True:
            PE_COMBINED_ACCUMULATOR = 0
            PE_MATTRESS_ACCUMULATOR = 0

app=App()

Answer 1

伪代码包括一个while 1循环，但实际代码没有。而且，从来没有调用过Inc()。我建议您在Inputs()末尾添加以下行

self.Inc()
self.root.after(10, self.Inputs)

您还必须使root成为一个实例变量，即在__init__()中包含self.root = root才能工作。