问题描述
我一直在尝试为椭圆制作左、右和缩放滑块,但我无法让它们全部同步工作。它们自己工作,但是当我尝试在混音中添加第二个滑块时,它们只是重置了它们的位置和比例。我使用 repl.it
编写代码。
这是我的代码:
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,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,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,variable=x_intvar,label='x coordinate',command=x_changed,background='#FFFF33')
radius_slider = tkinter.Scale(root,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,sticky=tkinter.W)
radius_slider.grid(row=1,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,outline='#000000',fill='#00FFFF')
root.mainloop()```
解决方法
您没有在 x
、y
和 r
中将 x_changed()
、y_changed()
和 radius_changed()
声明为全局:
def x_changed(new_intval):
global x
...
def y_changed(new_intval):
global y
...
def radius_changed(new_intval):
global r
...
其实你可以将三个函数合二为一,不需要将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,variable=x_intvar,label='x coordinate',background='#FFFF33')
radius_slider = tkinter.Scale(root,variable=radius_intvar,label='Radius ',background='#66FF66')