使用Python GUI创建按钮

Question

我正在尝试使用类在Python中创建Buttons，但在运行它时，按钮不会出现。以下是我的代码

#Button_2
#Using Classes

from Tkinter import * 

class Application(Frame):
    """A GUI application with three button"""

    def _init_(self, master):
        """ Initialise the Frame. """
        Frame._init_(self, master)
        self.grid()
        self.create_widgets()

    def create_widgets(self):
        #"""Create three buttons"""
        #Create first buttom
        self.btn1 = Button(self, text = "I do nothing")
        self.btn1.grid()

        #Create second button
        self.btn2 = Button(self)
        self.btn2.grid()
        self.btn2.configure(text = "T do nothing as well")

        #Create third button
        self.btn3 = Button(self)
        self.btn3.grid()    
        self.btn3.configure(text = "I do nothing as well as well")

    root = Tk()
    root.title("Lazy Button 2")
    root.geometry("500x500")
    app = Application(root)

    root.mainloop()

任何帮助将不胜感激

Answer 1

您需要将“构造函数”方法命名为__init__，而不是_init_。在编写时，grid和create_widgets方法永远不会被调用，因为_init_永远不会被调用。

Answer 2

好的，首先问题是您已声明以下代码：

root = Tk()
root.title("Lazy Button 2")
root.geometry("500x500")
app = Application(root)

root.mainloop()code here

在课堂内部。它应该在外面，所以这是一个缩进问题（也许是压缩的stackoverflow问题？）。

其次，我简化了代码以使其运行

from Tkinter import * 

class Application(Frame):
      """A GUI application with three button"""

     #create a class variable from the root (master):called by the constructor
     def _init_(self, master):
          self.master = master

     #simple button construction
     # create a button with chosen arguments
     # pack it after the creation not in the middle or before

     def create_widgets(self):
          #"""Create three buttons"""
          #Create first button
          btn1 = Button(self.master, text = "I do nothing")
          btn1.pack()

          #Create second button
          btn2 = Button(self.master, text = "T do nothing as well")
          btn2.pack()

         #Create third button
         btn3=Button(self.master, text = "I do nothing as well as well")
         btn3.pack()

  #must be outside class definition but probably due to stackoverlow
  root = Tk()
  root.title("Lazy Button 2")
  root.geometry("500x500")
  app = Application(root)
  #call the method
  app.create_widgets()
  root.mainloop()

这是一个起点，绝对有效，如下所示：

您可以使用grid（）而不是pack来解决问题，并从def init 构造函数中调用该方法。希望它有所帮助。

此调用方法也有效：

root = Tk()
root.title("Lazy Button 2")
root.geometry("500x500")
app = Application(root).create_widgets()  #creates and invokes
root.mainloop()

我的最后一次尝试也有效：

def __init__(self,master):
    self.master = master
    self.create_widgets()

接下来是：

root = Tk()
root.title("Lazy Button 2")
root.geometry("500x500")
app = Application(root)
root.mainloop()

最终代码：

from Tkinter import * 

class Application(Frame):
"""A GUI application with three button"""

def __init__(self,master):
    self.master = master
    self.create_widgets()



def create_widgets(self):
    #"""Create three buttons"""
    #Create first buttom
    btn1 = Button(self.master, text = "I do nothing")
    btn1.pack()

    #Create second button
    btn2 = Button(self.master, text = "T do nothing as well")
    btn2.pack()

    #Create third button
    btn3=Button(self.master, text = "I do nothing as well as well")
    btn3.pack()

root = Tk()
root.title("Lazy Button 2")
root.geometry("500x500")
app = Application(root)
root.mainloop()