python开发之tkinter实现图形随鼠标移动的方法

本文实例讲述了python开发之tkinter实现图形随鼠标移动的方法。分享给大家供大家参考，具体如下：

做这个东西的时候，灵感源自于一个js效果:

两个眼睛随鼠标移动而移动

运行效果：

代码部分：

    from tkinter import *
    #1.获取到小圆当前的圆心坐标(x1, y1)
    #2.获取到小圆移动的圆心坐标(x2, y2)
    #3.把小圆从坐标(x1, y1)移动到坐标(x2, y2)
    __author__ = {'name' : 'Hongten',
           'mail' : 'hongtenzone@foxmail.com',
           'blog' : 'http://blog.csdn.net/',
           'QQ': '648719819',
           'created' : '2013-09-20'}
    class Eay(Frame):
      def createWidgets(self):
        ## The playing field
        self.draw = Canvas(self, width=500, height=500)
        #鼠标位置
        self.mouse_x = 450
        self.mouse_y = 250
        #圆心坐标(x,y)
        self.oval_zero_x = 250
        self.oval_zero_y = 250
        #外面大圆半径
        self.oval_r = 100
        #里面小圆半径
        self.oval_R = 30
        self.oval_r1 = self.oval_r - self.oval_R + 0.5
        self.oval_r2 = self.oval_r - self.oval_R - 0.5
        #小圆
        self.letter_ball_x1 = 250
        self.letter_ball_y1 = 250
        # The ball 外面大圆
        self.ball = self.draw.create_oval((self.oval_zero_x - self.oval_r),
                         (self.oval_zero_y - self.oval_r),
                         (self.oval_zero_x + self.oval_r),
                         (self.oval_zero_y + self.oval_r),
                         fill="white")
        self.ball = self.draw.create_oval((self.oval_zero_x - self.oval_r1),
                         (self.oval_zero_y - self.oval_r1),
                         (self.oval_zero_x + self.oval_r1),
                         (self.oval_zero_y + self.oval_r1),
                         fill="blue")
        self.ball = self.draw.create_oval((self.oval_zero_x - self.oval_r2),
                         (self.oval_zero_y - self.oval_r2),
                         (self.oval_zero_x + self.oval_r2),
                         (self.oval_zero_y + self.oval_r2),
                         fill="white")
        #里面小圆
        self.ball_over = self.draw.create_oval((self.oval_zero_x - self.oval_R),
                            (self.oval_zero_y - self.oval_R),
                            (self.oval_zero_x + self.oval_R),
                            (self.oval_zero_y + self.oval_R),
                            fill="red")
        self.draw.pack(side=LEFT)
      def mouseMove(self, event):
        self.mouse_x = event.x
        self.mouse_y = event.y
        if SHOW_LOG:
          print('#' * 50)
          print('鼠标的坐标为：({}, {})'.format(self.mouse_x, self.mouse_y))
          print('小圆当前坐标为：({}, {})'.format(self.letter_ball_x1, self.letter_ball_y1))
        '''获取到小圆移动的圆心坐标(x2, y2)'''
        ax_x = abs(self.mouse_x - self.oval_zero_x)
        ax_y = abs(self.mouse_y - self.oval_zero_y)
        if SHOW_LOG:
          print('坐标A(oval_zero_x, oval_zero_y)到坐标X(mouse_x, mouse_y)的距离为AX')
          print('AX中ax_x = {}, ax_y = {}'.format(ax_x, ax_y))
        ax_len = ((ax_x ** 2) + (ax_y ** 2))**0.5
        if SHOW_LOG:
          print('AX的长度为：{}'.format(ax_len))
        #如果鼠标坐标在(ax_len > |r-R|)
        if ax_len > abs(self.oval_r - self.oval_R):
          ac_len = abs(self.oval_r - self.oval_R)
          if SHOW_LOG:
            print('AC的产度为:{}'.format(ac_len))
          if int(self.mouse_x - self.oval_zero_x) != 0:
            if int(self.mouse_y - self.oval_zero_y) != 0:
              #求直线斜率 y = kx + b
              k = (self.mouse_y - self.oval_zero_y)/(self.mouse_x - self.oval_zero_x)
              if SHOW_LOG:
                print('鼠标到大圆圆心的直线的斜率为：{}'.format(k))
              b = self.mouse_y - (k * self.mouse_x)
              ###################################################
              #小圆移动后的坐标
              #这里有三个条件：
              #  1.小圆的圆心坐标(x1, y1)在直线AC上(y = kx + b)
              #  2.(r-R)^2 = x1^2 + y1^2  由1,2可以得到 => (r-R)^2 = x1^2 + 2*x1*k*b + b^2  => x1有两个值，通过3判断x1的符号，从而求出y1
              #  3.if self.mousex_x > 0:
              #     x1 > 0
              #这是一个二元二次方程，方程的解有两组，不过通过鼠标的位置self.mouse_x(self.mouse_y)可以判断圆心坐标x1(y1)
              letter_ball_x2 = ((ac_len * (abs(self.mouse_x - self.oval_zero_x)))/ax_len) + self.letter_ball_x1
              letter_ball_y2 = (letter_ball_x2 * k) + b
              if SHOW_LOG:
                print('小圆当前坐标为：({}, {})'.format(self.letter_ball_x1, self.letter_ball_y1))
                print('小圆移动后坐标为：({}, {})'.format(letter_ball_x2, letter_ball_y2))
              #把小圆从坐标(x1, y1)移动到坐标(x2, y2)
              self.moved_x2 = letter_ball_x2 - self.letter_ball_x1
              self.moved_y2 = letter_ball_y2 - self.letter_ball_y1
              if SHOW_LOG:
                print('需要移动的距离是：({}, {})'.format(int(self.moved_x2), int(self.moved_y2)))
              self.draw.move(self.ball_over, int(self.moved_x2), int(self.moved_y2))
              self.letter_ball_x1 = letter_ball_x2
              self.letter_ball_y1 = letter_ball_y2
            else:
              print('鼠标在X轴上') 
          else:
            print('鼠标在Y轴上')
        else:
          if SHOW_LOG:
            print('小圆的移动后的坐标就是鼠标坐标')
          #小圆移动后的坐标
          letter_ball_x2 = self.mouse_x
          letter_ball_y2 = self.mouse_y
          if SHOW_LOG:
            print('小圆移动后坐标为：({}, {})'.format(letter_ball_x2, letter_ball_y2))
          #把小圆从坐标(x1, y1)移动到坐标(x2, y2)
          self.moved_x2 = letter_ball_x2 - self.letter_ball_x1
          self.moved_y2 = letter_ball_y2 - self.letter_ball_y1
          if SHOW_LOG:
            print('需要移动的距离是：({}, {})'.format(int(self.moved_x2), int(self.moved_y2)))
          self.draw.move(self.ball_over, int(self.moved_x2), int(self.moved_y2))
          self.letter_ball_x1 = letter_ball_x2
          self.letter_ball_y1 = letter_ball_y2
      def move_ball(self, *args):
        #当鼠标在窗口中按下左键拖动的时候执行
        #Widget.bind(self.draw, "<B1-Motion>", self.mouseMove)
        #当鼠标在大圆内移动的时候执行
        self.draw.tag_bind(self.ball, "<Any-Enter>", self.mouseMove)
      def __init__(self, master=None):
        global letter_ball_x2
        letter_ball_x2 = 0
        global letter_ball_y2
        letter_ball_y2 = 0
        global SHOW_LOG
        SHOW_LOG = True
        Frame.__init__(self, master)
        Pack.config(self)
        self.createWidgets()
        self.after(10, self.move_ball)
    game = Eay()
    game.mainloop()

希望本文所述对大家Python程序设计有所帮助。