Question

我正在尝试使用我的画布上的OnButtonAddClick函数在类mainWindow中打印一个矩形，但是当我尝试获取错误时： AttributeError：＆＃39; NoneType＆＃39;对象没有属性＆＃39; create_rectangle＆＃39;

这是关于OnButtonAddClick的功能，但我看不出有什么问题。我现在尝试了几件事，希望你能帮助我。

import tkinter as tk
import Calc as c

class mainWindow(tk.Frame):
    def __init__(self, master):
        tk.Frame.__init__(self, master)
        self.master = master
        self.Canvas()

        #more stuff

    def button(self):
        self.buttonAdd = tk.Button(self, text='Add', width=12, command=self.OnButtonAddClick).grid(column=2, row=10)

    ##more stuff

    def Canvas(self):
        "Projecting elements on canvas"
        self.canvas = tk.Canvas(self, width=500, height=500, borderwidth=20, bg='white').grid(column=5, row=2, rowspan=30)

    def OnButtonAddClick(self):
        self.canvas.create_rectangle(200,200,200,200)
        print('hi')

if __name__ == '__main__':
    root = tk.Tk()
    mainWindow(root).pack(side='top', fill='both')
    root.mainloop()

Answer 1

从初始化调用中分离布局调用：

    self.buttonAdd = tk.Button(...).grid(...)
    ...
    self.canvas = tk.Canvas(...).grid(...)

为：

    self.buttonAdd = tk.Button(...)
    self.buttonAdd.grid(...)
    ...
    self.canvas = tk.Canvas(...)
    self.canvas.grid(...)

tkinter在画布上打印功能

1 个答案: