无效的命令名称“帆布！”

Question

我试图创建一个帆布与100个完全随机的矩形出现，但我得到的是一个空白的画布，一个错误：“！帆布”

无效的命令名称

我该如何解决这个问题？

from tkinter import * 
import random 
tk = Tk() 
canvas = Canvas(tk, width=400, height=400) 
canvas.pack() 
tk.mainloop() 

def rndm_rect(width, height): 
    x1 = (random.randrange(width)) 
    y1 = (random.randrange(height)) 
    x2 = x1 + (random.randrange(width)) 
    y2 = y1 + (random.randrange(width)) 
    canvas.create_rectangle(x1, y1, x2, y2) 

rndm_rect(400, 400) 


for x in range(0, 100): 
    rndm_rect(400, 400) 

Answer 1

tk.mainloop()是用来启动事件循环的命令，因此你正在生成的窗口中，您已经声明为矩形位置的变量之前。

将tk.mainloop()在脚本的末尾，它运行良好，见下图：

from tkinter import * 
import random 
tk = Tk() 
canvas = Canvas(tk, width=400, height=400) 
canvas.pack() 

def rndm_rect(width, height): 
    x1 = (random.randrange(width)) 
    y1 = (random.randrange(height)) 
    x2 = x1 + (random.randrange(width)) 
    y2 = y1 + (random.randrange(width)) 
    canvas.create_rectangle(x1, y1, x2, y2) 

rndm_rect(400, 400) 


for x in range(0, 100): 
    rndm_rect(400, 400) 

tk.mainloop()