Graphics.py，我想在鼠标点击时创建三个单独的对象

Question

这就是我目前所拥有的，但我想做到这一点，我可以在窗口中单击三次，并在鼠标单击点处有三个不同颜色的圆圈。

from Graphics import *


def main():
    win = GraphWin("ball", 400, 400)
    win.setBackground('black')  
    
    while True:
        point = win.getMouse()
        if point.x > 20 and point.y > 20:             
            circ_1 = Circle(Point(point.x,point.y), 20)
            circ_1.setFill("white")
            circ_1.draw(win)
            continue        
        
        if point.x > 20 and point.y > 20:             
            circ_2 = Circle(Point(point.x,point.y), 20)
            circ_2.setFill("blue")
            circ_2.draw(win)    
            continue
        
        if point.x > 20 and point.y > 20:             
            circ_3 = Circle(Point(point.x,point.y), 20)
            circ_3.setFill("yellow")
            circ_3.draw(win)    
            continue        
       
    win.getMouse()
    win.close()    
main()

Answer 1

您可以将颜色保留在列表中，并使用变量来显示当前圆圈中要使用的颜色。画完圆圈后，您可以更改索引以在下一个圆圈中使用下一种颜色。当它使用最后一种颜色时，将索引移动到 0 以再次使用第一种颜色

from graphics import *


def main():
    colors = ['white', 'blue', 'yellow']
    color_index = 0
    
    win = GraphWin("ball", 400, 400)
    win.setBackground('black')  
    
    while True:
        point = win.getMouse()
        if point.x > 20 and point.y > 20:
            color = colors[color_index]
            print('color:', color)
            
            circ = Circle(Point(point.x,point.y), 20)
            circ.setFill(color)
            circ.draw(win)
            
            color_index += 1
            if color_index >= len(colors):
                color_index = 0
       
    win.close()    

main()

---

但我不会使用while True 循环，而是使用bind() 将左键单击分配给某些功能

from graphics import *

# global variables

colors = ['white', 'blue', 'yellow']
color_index = 0

win = None

def draw_circle(event):
    global color_index  # inform function to assign new value to global variable `color_index` instead of local variable `color_index`  because I will need this value when `mouse button` will run again this function

    print('event:', event)
    
    if event.x > 20 and event.y > 20:
        color = colors[color_index]
        print('color:', color)
        
        circ = Circle(Point(event.x, event.y), 20)
        circ.setFill(color)
        circ.draw(win)
        
        color_index += 1
        if color_index >= len(colors):
            color_index = 0

def main():
    global win  # inform function to assign new value to global variable `win` instead of local variable `win` because I need this value in other function
    
    win = GraphWin("ball", 400, 400)
    win.setBackground('black')

    win.bind('<Button-1>', draw_circle)  # function's name without `()`
    
    win.getMouse()
    win.close()
    
main()

---

在查看了Graphics 中的一些示例后，我发现它宁愿使用while True 而不是bind()

此版本使用键w、b、y改变颜色，q退出程序。

它需要checkMouse 而不是getMouse，因为它还必须同时使用checkKey，而getMouse 会阻塞代码。

from graphics import *

# global variables

current_color = 'white'
win = None

def draw_circle(event):
    print('event:', event)
    
    if event.x > 20 and event.y > 20:
       
        print('color:', current_color)
        
        circ = Circle(Point(event.x, event.y), 20)
        circ.setFill(current_color)
        circ.draw(win)

def main():
    global win  # inform function to assign new value to global variable instead of local variable
    global current_color
    
    win = GraphWin("ball", 400, 400)
    win.setBackground('black')

    while True:
        point = win.checkMouse()
        if point:
            draw_circle(point)
            
        key = win.checkKey()
        if key == 'w':
            current_color = 'white'
        elif key == 'y':
            current_color = 'yellow'
        elif key == 'b':
            current_color = 'blue'

        elif key == 'q':  # quit loop
            break
        
    win.close()
    
main()