python - Python tkinter复选框即使被选中也总是返回值0

它应该是GUI Pizza的订购单，所以它还有更多，但是我遇到的问题是，当它得到一个应该是oliveSelection的变量时，它在被检查时始终返回0，而不是1。

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

在选择时，橄榄选择总是返回0而不是1
print(olivesSelection)

最佳答案

您的程序中没有myGui.mainloop()。
TOPPING SELECTION不是有效的语句。同样，也不需要将以下几行缩进。
不要一行一行地创建和放置tkinter小部件，否则最终会得到一堆引用None的变量（pack()返回的值）。
像olivesSelection=a.get()这样的语句并没有按照您认为的方式执行。该语句调用a.get()，获得返回值0（因为它在程序启动时发生），然后将该0分配给olivesSelection。复选框不会更改该变量的值。如果希望事情随着复选框而动态发生，则必须trace()这些IntVar并将command添加到Checkbutton中。
永远不会调用checkToppings()。
检查olivesSelection==1是否总是False，因为a.get()在分配给0时为olivesSelection（请参见上文）。在此处使用a.get()。
如果在elif中使用checkToppings()，则只会在列表中添加一个顶部（第一个具有复选框的顶部）。
您不需要将==1用作仅是0或1的值-只需说if pepperoniSelection:。 1是真实值，而0是虚假值（从技术上讲，1实际上是True，而0实际上是False，因为bool是int的子类）。

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()