pythonttkinter复选框总是返回值为0，即使选中它们也是如此

Question

它应该是一个GUI批萨订单，所以它有更多，但我遇到的问题是，当它得到一个变量，它应该是oliveSelection时，它总是返回0，而不是1。在

from tkinter import *
myGui=Tk()
myGui.geometry("800x600")
myGui.title("Pete's Pizza Parlour~Order Form")


TOPPING SELECTION
    toppings_lbl=Label(myGui,text="Toppings:",font=("Good Times",10),fg="blue").pack()
    a=IntVar()
    olives_chk=Checkbutton(myGui,text="Olives",variable=a).pack()
    b=IntVar()
    tomatoes_chk=Checkbutton(myGui,text="Tomatoes",variable=b).pack()
    c=IntVar()
    pepperoni_chk=Checkbutton(myGui,text="Pepperoni",variable=c).pack()
    d=IntVar()
    hotPeppers_chk=Checkbutton(myGui,text="Hot Peppers",variable=d).pack()
    e=IntVar()
    onions_chk=Checkbutton(myGui,text="Onions",variable=e).pack()
    f=IntVar()
    ham_chk=Checkbutton(myGui,text="Ham",variable=f).pack()
    g=IntVar()
    sausage_chk=Checkbutton(myGui,text="Sausage",variable=g).pack()
    h=IntVar()
    greenPeppers_chk=Checkbutton(myGui,text="Green Peppers",variable=h).pack()

olivesSelection=a.get()
tomatoesSelection=b.get()
pepperoniSelection=c.get()
hotPeppersSelection=d.get()
onionsSelection=e.get()
hamSelection=f.get()
sausageSelection=g.get()
greenPeppersSelection=h.get()

olivesSelectionStr="olives"
tomatoesSelectionStr="tomatoes"
pepperoniSelectionStr="pepperoni"
hotPeppersSelectionStr="hot peppers"
onionsSelectionStr="onions"
hamSelectionStr="ham"
sausageSelectionStr="sausage"
greenPeppersSelectionStr="green peppers"
noToppingsStr="no toppings."
def checkToppings():
    toppingsList=""
    if(olivesSelection==1):
        toppingsList=toppingsList+olivesSelectionStr
    elif(tomatoesSelection==1):
        toppingsList=toppingsList+tomatoesSelectionStr
    elif(pepperoniSelection==1):
        toppingsList=toppingsList+pepperoniSelectionStr
    elif(hotPeppersSelection==1):
        toppingsList=toppingsList+hotPeppersSelectionStr
    elif(onionsSelection==1):
        toppingsList=toppingsList+onionsSelectionStr
    elif(hamSelection==1):
        toppingsList=toppingsList+hamSelectionStr
    elif(sausageSelection==1):
        toppingsList=toppingsList+sausageSelectionStr
    elif(greenPeppersSelection==1):
        toppingsList=toppingsList+greenPeppersSelectionStr
    else:
        toppingsList=noToppingsStr

橄榄色选择在选中时总是返回0而不是1 print(olivesSelection)

Answer 1

好吧，有几件事。在

你需要把你的topping.get()放在你的定义里面，这个定义需要添加配料。否则，您只是在运行程序时执行.get()，而不是按需执行

TOPPING SELECTION应该被注释掉，因为它没有其他用途

大的elif树不会对您有帮助，因为一旦您执行if语句True，您就要退出if块。另外，出于个人喜好和代码清洁度的考虑，您可能需要查找字典来了解这一点。一旦超过块中的3或4条if语句，它们就会变得相当混乱。在

另外，我知道您说过还有更多的代码，但是作为一个友好的提醒，以防您忘记了其余代码的底部，请确保您的主窗口实例输入mainloop()

from tkinter import *
myGui=Tk()
myGui.geometry("800x600")
myGui.title("Pete's Pizza Parlour~Order Form")

#TOPPING SELECTION
toppings_lbl=Label(myGui,text="Toppings:",font=("Good Times",10),fg="blue").pack()
a=IntVar()
olives_chk=Checkbutton(myGui,text="Olives",variable=a).pack()
b=IntVar()
tomatoes_chk=Checkbutton(myGui,text="Tomatoes",variable=b).pack()
c=IntVar()
pepperoni_chk=Checkbutton(myGui,text="Pepperoni",variable=c).pack()
d=IntVar()
hotPeppers_chk=Checkbutton(myGui,text="Hot Peppers",variable=d).pack()
e=IntVar()
onions_chk=Checkbutton(myGui,text="Onions",variable=e).pack()
f=IntVar()
ham_chk=Checkbutton(myGui,text="Ham",variable=f).pack()
g=IntVar()
sausage_chk=Checkbutton(myGui,text="Sausage",variable=g).pack()
h=IntVar()
greenPeppers_chk=Checkbutton(myGui,text="Green Peppers",variable=h).pack()

olivesSelectionStr="olives"
tomatoesSelectionStr="tomatoes"
pepperoniSelectionStr="pepperoni"
hotPeppersSelectionStr="hot peppers"
onionsSelectionStr="onions"
hamSelectionStr="ham"
sausageSelectionStr="sausage"
greenPeppersSelectionStr="green peppers"
noToppingsStr="no toppings."


def checkToppings():
    toppingsList=""
    olivesSelection=a.get()
    tomatoesSelection=b.get()
    pepperoniSelection=c.get()
    hotPeppersSelection=d.get()
    onionsSelection=e.get()
    hamSelection=f.get()
    sausageSelection=g.get()
    greenPeppersSelection=h.get()
    if(olivesSelection==1):
        toppingsList=toppingsList+olivesSelectionStr
    if(tomatoesSelection==1):
        toppingsList=toppingsList+tomatoesSelectionStr
    if(pepperoniSelection==1):
        toppingsList=toppingsList+pepperoniSelectionStr
    if(hotPeppersSelection==1):
        toppingsList=toppingsList+hotPeppersSelectionStr
    if(onionsSelection==1):
        toppingsList=toppingsList+onionsSelectionStr
    if(hamSelection==1):
        toppingsList=toppingsList+hamSelectionStr
    if(sausageSelection==1):
        toppingsList=toppingsList+sausageSelectionStr
    if(greenPeppersSelection==1):
        toppingsList=toppingsList+greenPeppersSelectionStr
    if toppingsList=="":
        toppingsList=noToppingsStr
    print(toppingsList)

topping_btn = Button(myGui,text='print toppings', command = checkToppings)
topping_btn.pack()
myGui.mainloop()

Answer 2

1. 您的程序中没有myGui.mainloop()。在
2. TOPPING SELECTION不是有效语句。而且，下面的行不需要是缩进块。在
3. 不要将tkinter小部件的创建和放置放在一行，否则您将得到一大堆引用None（由pack()返回的值）的变量。在
4. 像olivesSelection=a.get()这样的语句并没有像您所想的那样做。该语句调用a.get()，获取返回值0（因为它发生在程序启动时），然后将0分配给olivesSelection。复选框不会更改该变量的值。如果您希望在选中复选框时动态发生，则必须trace()这些IntVar，并将command添加到{}s中
5. checkToppings()从不调用。在
6. 检查olivesSelection==1是否总是False，因为a.get()在分配给olivesSelection时是{}（见上文）。在这里使用a.get()。在
7. 如果在checkToppings()中使用elif，它只会向列表中添加一个topping（第一个有复选框的topping）。在
8. 对于只有0或{}的值，您不需要使用==1只需说if pepperoniSelection:。1是一个真实值，0是一个错误的值（从技术上讲，1实际上是{}，而{}实际上是{}，因为{}是{}的子类）。在

---

from tkinter import *
myGui=Tk()
myGui.geometry("800x600")
myGui.title("Pete's Pizza Parlour~Order Form")


def checkem():
    print(a.get(), b.get(), c.get(), d.get(), e.get(), f.get(), g.get(), h.get())
    print(checkToppings())

toppings_lbl=Label(myGui,text="Toppings:",font=("Good Times",10),fg="blue")
toppings_lbl.pack()
a=IntVar()
olives_chk=Checkbutton(myGui,text="Olives",variable=a)
olives_chk.pack()
b=IntVar()
tomatoes_chk=Checkbutton(myGui,text="Tomatoes",variable=b)
tomatoes_chk.pack()
c=IntVar()
pepperoni_chk=Checkbutton(myGui,text="Pepperoni",variable=c)
pepperoni_chk.pack()
d=IntVar()
hotPeppers_chk=Checkbutton(myGui,text="Hot Peppers",variable=d)
hotPeppers_chk.pack()
e=IntVar()
onions_chk=Checkbutton(myGui,text="Onions",variable=e)
onions_chk.pack()
f=IntVar()
ham_chk=Checkbutton(myGui,text="Ham",variable=f)
ham_chk.pack()
g=IntVar()
sausage_chk=Checkbutton(myGui,text="Sausage",variable=g)
sausage_chk.pack()
h=IntVar()
greenPeppers_chk=Checkbutton(myGui,text="Green Peppers",variable=h)
greenPeppers_chk.pack()
thebutton = Button(myGui, text='check', command=checkem)
thebutton.pack()

olivesSelectionStr="olives"
tomatoesSelectionStr="tomatoes"
pepperoniSelectionStr="pepperoni"
hotPeppersSelectionStr="hot peppers"
onionsSelectionStr="onions"
hamSelectionStr="ham"
sausageSelectionStr="sausage"
greenPeppersSelectionStr="green peppers"
noToppingsStr="no toppings."

def checkToppings():
    toppings = [var for val,var in zip((a.get(), b.get(), c.get(), d.get(),
                                        e.get(), f.get(), g.get(), h.get()),
                                       (olivesSelectionStr, tomatoesSelectionStr,
                                        pepperoniSelectionStr, hotPeppersSelectionStr,
                                        onionsSelectionStr, hamSelectionStr,
                                        sausageSelectionStr, greenPeppersSelectionStr))
                if val]
    if not toppings:
        return 'no toppings.'
    elif len(toppings)==1:
        return toppings[0] + '.'
    elif len(toppings)==2:
        return ' and '.join(toppings) + '.'
    else:
        return ', '.join(toppings[:-1]) + ', and ' + toppings[-1] + '.'

myGui.mainloop()