Python 如何在Tkinter中固定滑块？

我一直在尝试为椭圆形制作一个左、右和缩放滑块，但我无法让它们同步工作。它们自己工作，但当我尝试在混合中添加第二个滑块时，它们只是重置其位置和比例。我使用

repl.it

来编写代码

这是我的密码：

import tkinter 

root = tkinter.Tk()
root.option_add('*Font', 'Times')

#####   MODEL  ######   
y_intvar = tkinter.IntVar()   #create special tk variable
y_intvar.set(150)             #set initial value
x_intvar = tkinter.IntVar()   
x_intvar.set(150)   
radius_intvar = tkinter.IntVar()
radius_intvar.set(150)          
r = 150                       #fixed value for radius
x = 150                       #fixed value for the x position
######   CONTROLLER   #########

# Event handler for slider
def y_changed(new_intval):
     #read the value of y slider
    y = y_intvar.get()
    # update the view
    canvas.coords(circle_item, x-r, y-r, x+r, y+r)
    
def x_changed(new_intval):
     #read the value of y slider
    x = x_intvar.get()
    # update the view
    canvas.coords(circle_item, x-r, y-r, x+r, y+r)

def radius_changed(new_intval):
    # Get data from model
    # Could do this: r = int(new_intval)
    r = radius_intvar.get()
    # Controller updating the view
    canvas.coords(circle_item, x-r, y-r, x+r, y+r)

#create the slider
Y_slider = tkinter.Scale(root, from_=1, to=300, variable=y_intvar, label='y coordinate', command=y_changed, background='#FF6666')

X_slider = tkinter.Scale(root, from_=1, to=300, variable=x_intvar, label='x coordinate', command=x_changed, background='#FFFF33')

radius_slider = tkinter.Scale(root, from_=1, to=300, variable=radius_intvar,label='Radius         ', command=radius_changed, background='#66FF66')

#place the slider in row1 and column0
Y_slider.grid(row=2, column=0, sticky=tkinter.W)
X_slider.grid(row=3, column=0, sticky=tkinter.W)
radius_slider.grid(row=1, column=0, sticky=tkinter.W)
#directions for the user
text = tkinter.Label(root, text='Drag slider \n to adjust \n circle.')
text.grid(row=0, column=0)

######   VIEW   ################### present the information to user

#need a canvas to draw the circle on
canvas = tkinter.Canvas(root, width=500, height=500, background='#FFFFFF')
canvas.grid(row=0, rowspan=9, column=1)

# Create a circle on the canvas 
y = y_intvar.get()
x = x_intvar.get()
r = radius_intvar.get()
circle_item = canvas.create_oval(x-r, y-r, x+r, y+r,outline='#000000', fill='#00FFFF')

root.mainloop()```

---

您未将

x

、

y

和

r

声明为全局内部

x\u已更改（）

、

y\u已更改（）

和

radius\u已更改（）

：

---

实际上，您可以将这三个函数合并为一个函数，而不需要将这三个变量声明为全局变量：

def on_changed(_):
    x = x_intvar.get()
    y = y_intvar.get()
    r = radius_intvar.get()
    canvas.coords(circle_item, x-r, y-r, x+r, y+r)

#create the slider
Y_slider = tkinter.Scale(root, from_=1, to=300, variable=y_intvar, label='y coordinate', command=on_changed, background='#FF6666')

X_slider = tkinter.Scale(root, from_=1, to=300, variable=x_intvar, label='x coordinate', command=on_changed, background='#FFFF33')

radius_slider = tkinter.Scale(root, from_=1, to=300, variable=radius_intvar,label='Radius         ', command=on_changed, background='#66FF66')

def on_changed(_):
    x = x_intvar.get()
    y = y_intvar.get()
    r = radius_intvar.get()
    canvas.coords(circle_item, x-r, y-r, x+r, y+r)

#create the slider
Y_slider = tkinter.Scale(root, from_=1, to=300, variable=y_intvar, label='y coordinate', command=on_changed, background='#FF6666')

X_slider = tkinter.Scale(root, from_=1, to=300, variable=x_intvar, label='x coordinate', command=on_changed, background='#FFFF33')

radius_slider = tkinter.Scale(root, from_=1, to=300, variable=radius_intvar,label='Radius         ', command=on_changed, background='#66FF66')