从其他类访问变量-自定义对话框

Question

I am trying to create a dialog that will get the a social security number (or simular input) from a pop up dialog, but when I try I get an error saying that the class does not have that attribute. Here is the code:

from Tkinter import *

class App:
    def __init__(self, master):
        b = Button(text="Click for social dialog", command=self.getSocial)
        b.grid(row=0, column=0)
    def getSocial(self):
        d = socialDialog(root)
        print d.social
class socialDialog:
    def __init__(self, master):
        self.top = Toplevel()
        Label(self.top, text='Social Security #: ').grid(row=0, column=0)
        self.entry = Entry(self.top)
        self.entry.grid(row=0, column=1)
        self.entry.focus_set()
        self.top.bind('<Key>', self.formatData)
        self.top.bind('<Return>', self.ok)
    def formatData(self, master):
        currentData = self.entry.get()
        if len(currentData) == 3:
            self.entry.insert(3, '-')
        elif len(currentData) == 6:
            self.entry.insert(6, '-')
        elif len(currentData) > 11:
            self.entry.delete(-1, END)
    def ok(self, master):
        self.social = self.entry.get()
        self.top.destroy()
root = Tk()
app = App(root)
root.mainloop()

Answer 1

The problem is your socialDialog class is only assigned a social attribute after you press Return, which invokes the ok method. Therefore when you call getSocial , which instantiates a socialDialog , and then immediately access the social attribute, the social attribute in the socialDialog instance doesn't exist yet.

I'm not sure what your long term goals for this code are, but an immediate fix would be to change the getSocial function thusly:

def getSocial(self):
    d = socialDialog(root)
    #  print d.social

then add

print self.social

to the ok method.

Answer 2

The problem is that print is executed immediately after the dialog is shown, because the dialog is not shown modally.

To fix that, try something like this:

d = socialDialog(root)
root.wait_window(d.top)
print d.social

But note that the error will still occur if the dialog is closed without entering anything. To prevent that, make sure the social attribute has a default value:

class socialDialog:
    social = None