Python tkinter事件高级用法实例

本文实例讲述了Python tkinter事件高级用法。分享给大家供大家参考，具体如下：

先来看看运行效果：

完整实例代码：

# -*- coding:utf-8-*-
#! python3
from tkinter import *
import threading, time
trace = 0
class CanvasEventsDemo:
 def __init__(self, parent=None):
   canvas = Canvas(width=300, height=300, bg='beige')
   canvas.pack()
   canvas.bind('<ButtonPress-1>', self.onStart)   # click
   canvas.bind('<B1-Motion>',   self.onGrow)    # and drag
   canvas.bind('<Double-1>',   self.onClear)   # delete all
   canvas.bind('<ButtonPress-3>', self.onMove)    # move latest
   self.canvas = canvas
   self.drawn = None
   self.kinds = [canvas.create_oval, canvas.create_rectangle]
 def onStart(self, event):
   self.shape = self.kinds[0]
   self.kinds = self.kinds[1:] + self.kinds[:1]   # start dragout
   self.start = event
   self.drawn = None
 def onGrow(self, event):               # delete and redraw
   canvas = event.widget
   if self.drawn: canvas.delete(self.drawn)
   objectId = self.shape(self.start.x, self.start.y, event.x, event.y)
   if trace: print(objectId)
   self.drawn = objectId
 def onClear(self, event):
   event.widget.delete('all')            # use tag all
 def onMove(self, event):
   if self.drawn:                  # move to click spot
     if trace: print(self.drawn)
     canvas = event.widget
     diffX, diffY = (event.x - self.start.x), (event.y - self.start.y)
     canvas.move(self.drawn, diffX, diffY)
     self.start = event
class CanvasEventsDemoTags(CanvasEventsDemo):
 def __init__(self, parent=None):
   CanvasEventsDemo.__init__(self, parent)
   self.canvas.create_text(100, 8, text='Press o and r to move shapes')
   self.canvas.master.bind('<KeyPress-o>', self.onMoveOvals)
   self.canvas.master.bind('<KeyPress-r>', self.onMoveRectangles)
   self.kinds = self.create_oval_tagged, self.create_rectangle_tagged
 def create_oval_tagged(self, x1, y1, x2, y2):
   objectId = self.canvas.create_oval(x1, y1, x2, y2)
   self.canvas.itemconfig(objectId, tag='ovals', fill='blue')
   return objectId
 def create_rectangle_tagged(self, x1, y1, x2, y2):
   objectId = self.canvas.create_rectangle(x1, y1, x2, y2)
   self.canvas.itemconfig(objectId, tag='rectangles', fill='red')
   return objectId
 def onMoveOvals(self, event):
   print('moving ovals')
   self.moveInSquares(tag='ovals')      # move all tagged ovals
 def onMoveRectangles(self, event):
   print('moving rectangles')
   self.moveInSquares(tag='rectangles')
 def moveInSquares(self, tag):         # 5 reps of 4 times per sec
   for i in range(5):
     for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]:
       self.canvas.move(tag, diffx, diffy)
       self.canvas.update()       # force screen redraw/update
       time.sleep(0.25)         # pause, but don't block gui
class CanvasEventsDemoThread(CanvasEventsDemoTags):
 def moveEm(self, tag):
   for i in range(5):
     for (diffx, diffy) in [(+20, 0), (0, +20), (-20, 0), (0, -20)]:
       self.canvas.move(tag, diffx, diffy)
       time.sleep(0.25)           # pause this thread only
 def moveInSquares(self, tag):
   threading.Thread(self.moveEm, (tag,)).start()
if __name__ == '__main__':
 CanvasEventsDemoThread()
 mainloop()

希望本文所述对大家Python程序设计有所帮助。

来源：http://www.cnblogs.com/hhh5460/p/5188527.html