Das deutsche Python-Forum

Code: Alles auswählen

#!/usr/bin/python3

import tkinter as t
from math import pi,cos
from time import sleep


class Oval(object):

   def __init__(self, canvas, cx, cy, rx, ry, color='black'):
      #
      self.canvas = canvas
      self.cx = cx
      self.cy = cy
      self.rx = rx
      self.ry = ry
      self.color = color
      #
      self.tt = 0
      self.coords = (
         self.cx-self.rx, self.cy-self.ry,
         self.cx+self.rx, self.cy+self.ry )
      self.graph_obj = self.canvas.create_oval(
         self.coords, fill=self.color)
      #
      self.run = False

   def animate_step(self):
      #
      self.tt += 1
      self.xx = self.rx*cos(self.tt*pi/128)
      self.coords = (
         self.cx - self.xx,
         self.cy - self.ry,
         self.cx + self.xx,
         self.cy + self.ry
         )
      #
      self.canvas.coords(self.graph_obj, self.coords)


class Bild(object):
 
   def __init__(self):
      #
      root = t.Tk()
      #
      self.canvas = t.Canvas(root,bg='white')
      self.canvas.pack()
      button = t.Button(root,text='start/stop',command=self.startstop)
      button.pack()
      #
      cx = 150; cy = 120; rx = 100; ry = 100
      self.oval = Oval(self.canvas, cx, cy, rx, ry)
      #
      cx = 150; cy = 120; rx = 80; ry =  80
      self.oval_red = Oval(self.canvas, cx, cy, rx, ry, 'red')
      #
      self.run = False

   def startstop(self):
      self.run = not self.run
      #
      while self.run:
         self.oval.animate_step()
         self.oval_red.animate_step()
         #
         self.canvas.update()
         sleep(0.01)


bild = Bild()
t.mainloop()

Code: Alles auswählen

This method forces the updating of the display. It should be used only if you know what you're
doing, since it can lead to unpredictable behavior or looping. It should never be called from an event
callback or a function that is called from an event callback.

Code: Alles auswählen

>>> import Tkinter
>>> root = Tkinter.Tk()
>>> help(root.after)
Help on method after in module Tkinter:

after(self, ms, func=None, *args) method of Tkinter.Tk instance
    Call function once after given time.
    
    MS specifies the time in milliseconds. FUNC gives the
    function which shall be called. Additional parameters
    are given as parameters to the function call.  Return
    identifier to cancel scheduling with after_cancel.

Code: Alles auswählen

import Tkinter
import time

def go_btn():
  textbox.insert('end', 'START')
  for zaehler in range(5):
    time.sleep(2)
    knopf2.after(1000,tuwas)
    textbox.insert('end', '\n'+str(zaehler))    
    # 1)
    # Ist diese Zeile aktiv, wird nach jedem Schleifendurchlauf geprueft ob die
    # Bedingungen fuer die after-Methode bereits erfuellt sind
    root.update()
  # 2)
  # Ist diese Zeile aktiv, wird der Button an dem die after Methode gebunden ist
  # zerstoert bevor der "mainloop" oder "update" eine Gelegenheit hat die Methode
  # auszuloesen. Resultat -> "tuwas" wird nie aufgerufen
  #knopf2.destroy()

  # 3)
  # Ist diese Zeile aktiv, werden jetzt alle after-Methoden aufgerufen deren 
  # "Zeitvorgabe" bereits abgelaufen ist.
  #root.update()

  textbox.insert('end', '\n\nENDE')


def tuwas():
  textbox.insert('end','\nund jetzt kommt die Fktn "tuwas"')

root = Tkinter.Tk()
knopf1 = Tkinter.Button(root, text='GO', command=go_btn)
knopf1.grid(row=1, column=0)
knopf2 = Tkinter.Button(root, text='GO2')
knopf2.grid(row=1, column=1)
textbox = Tkinter.Text(root)
textbox.grid(row=0, column=0, columnspan=2)

root.mainloop()