蟒蛇Tk的接口：NameError：全局名称“盒1”没有定义

Question

from Tkinter import * 
import MySQLdb 

def tran() : 
first= Tk() 

label1 = Label(first ,text="From") 
label1.pack() 

box1=Entry(first) 
box1.pack() 

label2=Label(first ,text="To") 
label2.pack() 

box2=Entry(first) 
box2.pack() 

label3=Label(first ,text="Amt") 
label3.pack() 

box3=Entry(first) 
box3.pack() 

Button1 = Button(first , text="Next", command=func3).pack() 


def func3() : 
conn = MySQLdb.connect (host = "localhost", user = "root", passwd = "natty", db = "dbms") 
cursor=conn.cursor() 

From=int(box1.get().strip()) 
To=int(box2.get().strip()) 
Amt=int(box3.get().strip()) 

cursor.execute ("select bal from account where acc="+str(From)+"") 

a=cursor.fetchone() 
fromval=int(a[0]) 

cursor.execute ("select bal from account where acc="+str(To)+"") 

b=cursor.fetchone() 
toval=int(b[0]) 

fromval=fromval-Amt 
toval=toval+Amt 

cursor.execute("update account set bal="+str(fromval)+" where acc="+str(From)+"") 
cursor.execute("update account set bal="+str(toval)+" where acc="+str(To)+"") 

cursor.close() 
conn.close() 

master = Tk() 
Button3 = Button(master, text="Transaction", command=tran).pack() 
mainloop() 

screen shot

下一个按钮不工作。当我点击“下一步”按钮，我发现了以下错误：

 
File "disp.py", line 24, in func3 
    From = int (box1.get().strip()) 
NameError: global name 'box1' is not defined 

我应该必须把FUNC3

Answer 1

你的代码改成这样：

from Tkinter import * 

import MySQLdb 

class App: 

    def __init__(self, master): 
     Button3 = Button(master, text="Transaction", command=self.tran).pack() 

    def tran(self) : 

     first = Tk() 

     label1 = Label(first ,text="From") 

     label1.pack() 

     self.box1=Entry(first) 

     self.box1.pack() 

     label2=Label(first ,text="To") 

     label2.pack() 

     self.box2=Entry(first) 

     self.box2.pack() 


     label3=Label(first ,text="Amt") 

     label3.pack() 

     self.box3=Entry(first) 

     self.box3.pack() 

     Button1 = Button(first , text="Next", command=self.func3).pack() 


    def func3(self) : 

     conn = MySQLdb.connect (host = "localhost", user = "root", passwd = "natty", db = "dbms") 

     cursor=conn.cursor() 

     From=int(self.box1.get().strip()) 

     To=int(self.box2.get().strip()) 

     Amt=int(self.box3.get().strip()) 
     cursor.execute ("select bal from account where acc="+str(From)+"") 

     a=cursor.fetchone() 

     fromval=int(a[0]) 

     cursor.execute ("select bal from account where acc="+str(To)+"") 

     b=cursor.fetchone() 

     toval=int(b[0]) 

     fromval=fromval-Amt 

     toval=toval+Amt 

     cursor.execute("update account set bal="+str(fromval)+" where acc="+str(From)+"") 

     cursor.execute("update account set bal="+str(toval)+" where acc="+str(To)+"") 

     cursor.close() 

     conn.close() 

master = Tk() 

app = App(master) 

master.mainloop() 

我认为应该工作。

Answer 2

BOX1是在TRAN（）函数的内部定义，并且因此（作为错误消息表示）内的按钮没有全局定义。