Tkinter-包含按钮的类

问题是你没有打包(或网格或放置)你的 MainApplication 自从你 主要应用程序 tk.Frame 类,其实例是小部件,因此需要打包到其主程序中。

def main():
    root = tk.Tk()
    app = MainApplication(root)     <--- here: where does it go in the root?
    root.mainloop()

app.pack()

您必须将导航栏放置在父帧中,使用 pack 或 grid

import Tkinter as tk

class MainApplication(tk.Frame):
    def __init__(self, parent, *args, **kwargs):
        tk.Frame.__init__(self, parent, *args, **kwargs)
        self.parent = parent
        self.navbar = NavBar(self)   
        self.navbar.grid(row=0, column=0)
        self.pack()             # <-- here ---------

class NavBar(tk.Frame):
    def __init__(self, parent):
        tk.Frame.__init__(self, parent)
        self.parent = parent
        self.fetchDataBtn = tk.Button(self, text='Fetch data')
        self.filterDataBtn = tk.Button(self, text='Filter data')

        self.fetchDataBtn.pack(padx=5, pady=10, side=tk.LEFT)
        self.filterDataBtn.pack(padx=5, pady=20, side=tk.LEFT)

def main():
    root = tk.Tk()
    app = MainApplication(root)
    # app.pack()   # <-- or here for a better control of the placement of several instances
    root.mainloop()

if __name__ == '__main__':
    main()

感谢@RightLeg指出了最初的错误。