Question

from tkinter import *
import random as r
import time as t

top = Tk()
top.resizable(0,0)
top.title("Dice Roll")
C = Canvas(top,height=500,width=370,bg="lawn green")
v = StringVar()
r4 = StringVar()
r6 = StringVar()
r12 = StringVar()
diceR = 0
def SetR(newR):
    diceR=newR
def GetR():
    return diceR
class Menu():
    def choose4():
        v.set("You have chosen: 4 sided die")
        SetR(1)
    def choose6():
        v.set("You have chosen: 6 sided die")
        SetR(2)
    def choose12():
        v.set("You have chosen: 12 sided die")
        SetR(3)
    def exitB():
        top.destroy()
class Dice():
    def roll():
        print(diceR)
        if diceR == 1:
            print("Test for 1")
        elif diceR == 2:
            print("Test for 2")
        elif diceR == 3:
            print("Test for 3")

choose4 = Button(text="Choose 4 sided die",command=Menu.choose4,wraplength=50)
choose6 = Button(text="Choose 6 sided die",command=Menu.choose6,wraplength=50)
choose12 = Button(text="Choose 12 sided die",command=Menu.choose12,wraplength=50)
exitB = Button(text="Exit",command=Menu.exitB)
roll = Button(text="Roll",command=Dice.roll,font=("calibri",20))
youChose = Label(top,textvariable=v)
rolled4 = Label(top,textvariable=r4)


C.pack()
choose4.place(height=76,width=75,x=1,y=425)
choose6.place(height=76,width=75,x=75,y=425)
choose12.place(height=76,width=75,x=149,y=425)
exitB.place(height=76,width=75,x=298,y=425)
youChose.place(x=1,y=1)
roll.place(height=76,width=75,x=223,y=425)
top.mainloop()

出于某种原因，按下按钮后变量diceR恢复为0 - 我希望此按钮将变量设置为1,2或3（参见代码）

我想要一个按钮将变量diceR设置为一个数字，这样我就可以使用这个新变量来改变＆＃34; roll＆＃34;的功能。按钮 - 但变量仍然设置回0。

我不知道我做错了什么，也不是最喜欢蟒蛇的人，所以你能否对这种情况有所了解？

Answer 1

因为您要在diceR内分配新的本地名称SetR，而不是“全局”diceR。然后在函数结束时丢弃该值。您需要明确指定要分配的名称：

def SetR(newR):
    global diceR
    diceR = newR

以下是您可以运行以演示此内容的最小示例：

val = 1

def local_val():
    val = 2

def global_val():
    global val 
    val = 3

print(val) # will be 1

local_val()
print(val) # will still be 1

global_val()
print(val) # will be 3

按下按钮后，为什么变量会恢复原始值（Tkinter）？

1 个答案: