如何让多个椭圆在画布上移动？

Question

我的问题是如何让多个带有随机数的“气泡”在屏幕上移动？

我必须做一堆 def bubble(): 还是有更简单的方法来做？在画布上随机移动“气泡”也让我感到困惑。

到目前为止的编码：

from tkinter import *
import random

def quit():
    root.destroy()


def bubble():
    xval = random.randint(5,765)
    yval = random.randint(5,615)
    canvas.create_oval(xval,yval,xval+30,yval+30, fill="#00ffff",outline="#00bfff",width=5)
    canvas.create_text(xval+15,yval+15,text=number)
    canvas.update()

def main():
    global root
    global tkinter
    global canvas
    root = Tk()
    root.title("Math Bubbles")
    Button(root, text="Quit", width=8, command=quit).pack()
    Button(root, text="Start", width=8, command=bubble).pack()
    canvas = Canvas(root, width=800, height=650, bg = '#afeeee')
    canvas.pack()
    root.mainloop()

# Create a sequence of numbers to choose from. CAPS denotes a constant variable
NUMBERS = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)

# Pick numbers randomly from the sequence with the help of a random.choice function
number = random.choice(NUMBERS)

# Create a variable to use later to see if the guess is correct
correct = number

main()

Answer 1

这应该可以帮助您：

import Tkinter, random

class BubbleFrame:

    def __init__(self, root):
        root.title("Math Bubbles")
        Tkinter.Button(root, text="Add Bubbles", width=8, command=self.bubble).pack()
        Tkinter.Button(root, text="Quit", width=8, command=quit).pack()
        self.canvas = Tkinter.Canvas(root, width=800, height=650, bg = '#afeeee')
        self.canvas.pack()
        self.bubbles = {} # this will hold bubbles ids, positions and velocities

    def bubble(self):
        # add bubbles for numbers from 1 to 20
        for number in range(1, 20+1):
            xval = random.randint(5,765)
            yval = random.randint(5,615)
            s1 = self.canvas.create_oval(xval,yval,xval+30,yval+30, fill="#00ffff",outline="#00bfff",width=5)
            s2 = self.canvas.create_text(xval+15,yval+15, text=number)
            self.bubbles[(s1, s2)] = (xval, yval, 0, 0) # add bubbles to dictionary

    def loop(self, root):
        for (s1, s2), (x, y, dx, dy) in self.bubbles.items():
            # update velocities and positions
            dx += random.randint(-1, 1)
            dy += random.randint(-1, 1)
            # dx and dy should not be too large
            dx, dy = max(-5, min(dx, 5)), max(-5, min(dy, 5))
            # bounce off walls
            if not 0 < x < 770: dx = -dx
            if not 0 < y < 620: dy = -dy
            # apply new velocities
            self.canvas.move(s1, dx, dy)
            self.canvas.move(s2, dx, dy)
            self.bubbles[(s1, s2)] = (x + dx, y + dy, dx, dy)
        # have mainloop repeat this after 100 ms
        root.after(100, self.loop, root)

if __name__ == "__main__":
    root = Tkinter.Tk()
    frame = BubbleFrame(root)
    frame.loop(root)
    root.mainloop()

请注意，我已经对代码进行了一些重组，使用一个类来包装这些方法和属性，但这完全取决于您。另请注意，我已使用 Python 2.7 完成此操作，因此可能需要进行一些小的修改，例如 Tkinter 包的名称。

您不需要为要添加的每个气泡定义另一个bubble 函数——实际上您的代码已经在画布上添加了许多气泡，所以这部分没问题。棘手的一点是移动气泡。

为此，我首先添加了 self.bubbles 字典，将气泡的 ID 及其标签（由 canvas.create... 方法返回）映射到它们当前的位置和速度。最后，loop 方法更新气泡的位置和速度并重新绘制画布。最后，此方法将使用after 方法安排下一次执行。