
为什么我程序里的这三个变量没变虚?
"""测试canvas组件的基本用法,使用面向对象的方式"""
from tkinter import *
from tkinter import messagebox
import random
class Application(Frame):
def __init__(self,master=None):
super().__init__(master) # super()代表的是父类的定义,而不是父类对象
self.master = master
self.pack()
self.createWidget()
def createWidget(self):
self.canvas = Canvas(self,width=300,height=200,bg="green")
self.canvas.pack()
#画一条直线
line=self.canvas.create_line(10,10,30,20,40,50)
#画一个矩形
rect=self.canvas.create_rectangle(50,50,100,100)
#画一个椭圆,坐标两双。为椭圆的边界矩形左上角和底部右下角
oval=self.canvas.create_oval(50,50,100,100)
global photo
photo = PhotoImage(file="image/logo.gif")
self.canvas.create_image(150,170,image=photo)
Button(self,text="画10个矩形",
command=self.draw50Recg).pack(side="left")
def draw50Recg(self):
for i in range(0,10):
x1 = random.randrange(int(self.canvas["width"])/2)
y1 = random.randrange(int(self.canvas["height"])/2)
x2 = x1+random.randrange(int(self.canvas["width"])/2)
y2 = y1+random.randrange(int(self.canvas["height"])/2)
self.canvas.create_rectangle(x1,y1,x2,y2)
if __name__ == '__main__':
root = Tk()
root.geometry("400x300+200+300")
app = Application(master=root)
root.mainloop()