我不知道为什么这个简单的Python代码没有运行

Question

我在此代码思路运行与Tkinter的那取决于我按下键盘上数字的”七段显示灯的应用程序。

import tkinter as tk
import keyboard
import time
from PIL import ImageTk, Image

def main():
    window = tk.Tk()
    window.title("AutoSegment")
    window.geometry("459x767")
    path=r"C:\Users\The Man Himself\Desktop\SSG\welcome.jpg"
    img = ImageTk.PhotoImage(Image.open(path))
    panel = tk.Label(window, image = img).pack(side = "bottom", fill = "both", expand = "yes")
    listener()
    tk.mainloop()

def set(name):
    path=r"C:\Users\The Man Himself\Desktop\SSG\%s.jpg" %name
    img = ImageTk.PhotoImage(Image.open(path))
    panel = tk.Label(window, image = img).pack(side = "bottom", fill = "both", expand = "yes")
    listener()
    tk.mainloop()

def listener():
    while True:
        try:
            if keyboard.is_pressed('1'):
                set("1")
                break
            elif keyboard.is_pressed('2'):
                set("2")
                break
            elif keyboard.is_pressed('3'):
                set("3")
                break
            elif keyboard.is_pressed('4'):
                set("4")
                break
            elif keyboard.is_pressed('5'):
                set("5")
                break
            elif keyboard.is_pressed('6'):
                set("6")
                break
            elif keyboard.is_pressed('7'):
                set("7")
                break
            elif keyboard.is_pressed('8'):
                set("8")
                break
            elif keyboard.is_pressed('9'):
                set("9")
                break
            elif keyboard.is_pressed('0'):
                set("0")
                break
        except:
            set("error")

main()

Answer 1

我还没有与keyboard模块的工作，但我可以告诉你如何不用它的工作。

一对夫妇的事情;被这意味着名称window是局部的功能的功能内创建的窗口。相反，创造在全球范围内的窗口。另外，功能set()是一个内置的功能，如果你重新定义它，你将不能访问内置函数。我把它称为set_display()代替。

正如您将在panel改变形象，最好在全局命名空间创建它。此外，为了能够改变它，你必须保持一个参考，即给它取名panel，然后包装。否则，该名称panel将指向从pack()的返回值是= None。

当您以后更改图像中的标签在功能set_display()还必须保存在标签中的图像的引用，明确在我的示例代码注释。

然后我使用bind()挂钩键盘这是在窗口小部件的Tkinter的标准方法。从那以后，我开始mainloop()它等待，直到按下一个键，然后调用keypress()。

import tkinter as tk
from PIL import ImageTk, Image

def set_display(name):
    path = r"C:\Users\The Man Himself\Desktop\SSG\%s.jpg" %name
    img = ImageTk.PhotoImage(Image.open(path))
    panel.config(image=img) # Load new image into label
    panel.image = img       # Save reference to image

def keypress(event):
    if event.char == '':    # Shift, ctrl etc, returns empty char
        set_display('error')
    elif event.char in '1234567890':    # Hook all numbers
        set_display(event.char)
    else:
        set_display('error')

window = tk.Tk()
window.title("AutoSegment")
window.geometry("459x767")

# Create Seven Segment Display label in global namespace
path = r"C:\Users\The Man Himself\Desktop\SSG\welcome.jpg"
img = ImageTk.PhotoImage(Image.open(path))
panel = tk.Label(window, image=img)
panel.pack(side="bottom", fill="both", expand="yes")

window.bind('<KeyPress>', keypress)
window.mainloop()