“停止"Tkinter 中的按钮 [英] "Stop" Button in Tkinter

问题描述

我正在尝试让海龟动画以按钮开始并以按钮停止.从按钮开始很容易，但我似乎无法找出停止按钮?到目前为止，这是我的代码:

I'm trying to have a turtle animation start with a button and stop with a button. It's very easy to start with a button but I can't seem to be able to figure out a stop button? Here's my code so far:

import turtle
import tkinter as tk
def start():
    t.forward(100)
    t.right(90)
    t.forward(100)
    t.left(90)
    t.forward(100)
    t.right(90)
    t.forward(100)
    t.right(90)
    t.forward(100)

def stop():
    t.stop

def clear():
    canvas.delete("all")

root = tk.Tk()
canvas = tk.Canvas(width = 500, height = 500)
canvas.pack()

t = turtle.RawTurtle(canvas)

tk.Button(text = "Start", command = start).pack(side = tk.LEFT)
tk.Button(text = "Stop", command = stop).pack(side = tk.LEFT)
tk.Button(text = "Clear", command = clear).pack(side = tk.LEFT)

root.mainloop()

清除按钮也起作用，但之后开始按钮不再起作用.如果有人也可以帮助我.

Also the clear button works but afterwards the start button doesn't work anymore. If someone can help me with that as well.

感谢@Mike - SMT 帮助我处理此代码.这是经过编辑且功能齐全的代码:

Thank you to @Mike - SMT for helping me with this code. Here's the edited and fully functioning code:

import turtle
import tkinter as tk


def start(turtle_object, draw_path):
    global tracker, start_ndex, end_ndex, started
    tracker = False
    if started == False:
        started = True
        for i in range(start_ndex, end_ndex):
            if tracker == False and i <= end_ndex:
                pth = draw_path[i]
                if pth[0] == "f":
                    turtle_object.forward(pth[1])
                elif pth[0] == "r":
                    turtle_object.right(pth[1])
                elif pth[0] == "l":
                    turtle_object.left(pth[1])
                start_ndex += 1


running = True

def stop():
    global tracker, started
    tracker = True
    started = False

def clear():
    global t, tracker, started, start_ndex
    t.reset()
    start_ndex = 0
    started = False
    t = turtle.RawTurtle(canvas)


root = tk.Tk()
tracker = False
start_ndex = 0
started = False # added this tracking variable to prevent issues with     spamming the start button.

draw_path = [["f", 100], ["r", 90], ["f", 100], ["l", 90], ["f", 100], ["r", 90], ["f", 100], ["r", 90], ["f", 100]]


end_ndex = len(draw_path)

canvas = tk.Canvas(width = 500, height = 500)
canvas.pack()

t = turtle.RawTurtle(canvas)
tk.Button(text = "Start", command = lambda: start(t, draw_path)).pack(side = tk.LEFT)
tk.Button(text = "Stop", command = stop).pack(side = tk.LEFT)
tk.Button(text = "Clear", command = clear).pack(side = tk.LEFT)
root.mainloop()

推荐答案

除非您在绘制的每条线之间提供检查器，否则您无法停止每个绘制语句.

You cannot stop each draw statement unless you provide a checker in between each line drawn.

下面的代码只是一个粗略的模型，你可以做一些事情来检查跟踪变量，用来告诉它不再画新线.

The below code is just a rough mock up of how you could make something to check for a tracking variable used to tell it to no longer draw new lines.

你能做的最接近停止绘画的事情是这样的:

The closest thing you can do to being able to stop drawing is something like this:

import turtle
import tkinter as tk

def start():
    global tracker
    tracker = False
    if tracker == False:
        t.forward(100)
    if tracker == False:
        t.right(90)
    if tracker == False:
        t.forward(100)
    if tracker == False:
        t.left(90)
    if tracker == False:
        t.forward(100)
    if tracker == False:
        t.right(90)
    if tracker == False:
        t.forward(100)
    if tracker == False:
        t.right(90)
    if tracker == False:
        t.forward(100)


def stop():
    global tracker
    tracker = True

def clear():
    canvas.delete("all")

root = tk.Tk()
tracker = False
canvas = tk.Canvas(width = 500, height = 500)
canvas.pack()

t = turtle.RawTurtle(canvas)

tk.Button(text = "Start", command = start).pack(side = tk.LEFT)
tk.Button(text = "Stop", command = stop).pack(side = tk.LEFT)
tk.Button(text = "Clear", command = clear).pack(side = tk.LEFT)

root.mainloop()

这至少会在每条线之后停止绘制，但您不能停止绘制中线.

This will at least stop drawing after each line but you cannot stop mid line draw.

只是为了好玩，如果我们添加一些跟踪变量并使用一些更清晰的逻辑，我们就可以开始、停止和重新开始.

Just for the fun of it if we add some tracking variables and use some cleaner logic we can start, stop and start again.

更新:从下面@cdlane 的评论中，我添加了附加跟踪并更新了清除功能.这应该允许启动停止启动而不会出现问题，并且还能够清除该字段.

Update: From @cdlane's comment below I have added addition tracking and updated the clear function. This should allow for start stop start without issues and also be able to clear the field.

import turtle
import tkinter as tk

def start(turtle_object, draw_path):
    global tracker, start_ndex, end_ndex, started
    tracker = False
    if started == False:
        started = True
        for i in range(start_ndex, end_ndex):
            if tracker == False and i <= end_ndex:
                pth = draw_path[i]
                if pth[0] == "f":
                    turtle_object.forward(pth[1])
                elif pth[0] == "r":
                    turtle_object.right(pth[1])
                elif pth[0] == "l":
                    turtle_object.left(pth[1])
                start_ndex += 1

def stop():
    global tracker, started
    tracker = True
    started = False

def clear():
    global t, tracker, started, start_ndex
    canvas.delete("all")
    tracker = False
    start_ndex = 0
    started = False
    t = turtle.RawTurtle(canvas)

root = tk.Tk()
tracker = False
start_ndex = 0
started = False # added this tracking variable to prevent issues with spamming the start button.

draw_path = [["f", 100], ["r", 90], ["f", 100], ["l", 90], ["f", 100], ["r", 90], ["f", 100], ["r", 90], ["f", 100]]


end_ndex = len(draw_path)

canvas = tk.Canvas(width = 500, height = 500)
canvas.pack()

t = turtle.RawTurtle(canvas)
tk.Button(text = "Start", command = lambda: start(t, draw_path)).pack(side = tk.LEFT)
tk.Button(text = "Stop", command = stop).pack(side = tk.LEFT)
tk.Button(text = "Clear", command = clear).pack(side = tk.LEFT)
root.mainloop()

这篇关于“停止"Tkinter 中的按钮的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！