以下Tkinter计划有什么问题?

时间:2014-11-25 14:09:43

标签: python tkinter

我试图执行我的第一个tkinter应用,但是它给了我错误,如下所示。不知道为什么'框架'对于同一个类的函数是不可见的?

Traceback (most recent call last):
File "C:\Data\Personal\Python\Tkinter\GUI_ver1.py", line 25, in <module>
myapp = App(root)
File "C:\Data\Personal\Python\Tkinter\GUI_ver1.py", line 7, in __init__
self.createWidgets()
File "C:\Data\Personal\Python\Tkinter\GUI_ver1.py", line 10, in createWidgets
self.button = Button(frame, text="QUIT", fg="red", command=frame.quit)
NameError: global name 'frame' is not defined

我的计划如下:

from Tkinter import *

class App(Frame):
    def __init__(self, master=None):
        frame = Frame(master)
        frame.pack()
        self.createWidgets()

    def createWidgets(self):
        self.button = Button(frame, text="QUIT", fg="red", command=frame.quit)
        self.button.pack(side=LEFT)

        self.hi_there = Button(frame, text="Hello", command=self.say_hi)
        self.hi_there.pack(side=LEFT)

        self.hi_there.pack({"side": "right"})

    def say_hi(self):
        print "hi there, everyone!"

root = Tk()
# create the application
myapp = App(root)

myapp.master.title("My First App")
myapp.master.geometry('450x130')
myapp.master.resizable(0,0)

# start the program
root.mainloop()

1 个答案:

答案 0 :(得分:3)

def __init__(self, master=None):
    frame = Frame(master)
    frame.pack()
    self.createWidgets()

您在frame中定义的__init__在任何其他方法中都不可见。如果您希望能够访问它,则需要将其设为self

的属性
def __init__(self, master=None):
    self.frame = Frame(master)
    self.frame.pack()
    self.createWidgets()

每当您使用变量时,请不要忘记包含self.

def createWidgets(self):
    self.button = Button(self.frame, text="QUIT", fg="red", command=self.frame.quit)
    self.button.pack(side=LEFT)

    self.hi_there = Button(self.frame, text="Hello", command=self.say_hi)
    self.hi_there.pack(side=LEFT)

这是解决NameError的最简单方法,但您的代码仍会因AttributeError: App instance has no attribute 'master'错误而崩溃。发生这种情况的原因是,虽然您将App作为Frame的子类,但您从不为它调用Frame初始值设定项,因此当您尝试调用Frame方法时会感到困惑。请记得致电__init__

def __init__(self, master=None):
    Frame.__init__(self, master)
    frame = Frame(master)
    frame.pack()
    self.createWidgets()

最后一次添加,你的代码应该正常工作,但它比它需要的复杂一点。您的App实例是一个框架,但它本身也包含一个框架self.frame。您可以通过删除第二帧并直接将小部件添加到self来简化此操作。

class App(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()
        self.createWidgets()

    def createWidgets(self):
        self.button = Button(self, text="QUIT", fg="red", command=self.quit)
        self.button.pack(side=LEFT)

        self.hi_there = Button(self, text="Hello", command=self.say_hi)
        self.hi_there.pack(side=LEFT)

        self.hi_there.pack({"side": "right"})