Python 3：Tkinter和更新帧

Question

我目前遇到的问题是，当我添加新班次时，我无法让GUI正常更新。目前，我似乎得到的最好的是获取更新的信息，但它显示在旧信息之上。

我确实阅读了整个mainloop()问题，并尝试使用after()方法，但我不确定这是不是我要找的：

class ViewShifts(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        buttonFrame = tk.Frame(self)
        buttonFrame.pack(side='bottom', fill='both', expand=True)

        #frame to display shifts
        table = tk.Frame(self)
        table.pack(side='top', fill='both', expand=True)
        table.destroy()

        #dictionary which will contain widgets that will display shifts (in viewNew method)
        self.widgets = {}

        button1= tk.Button(self, text="Home",
                           command=lambda: controller.showFrame(StartPage))
        button1.pack(padx=0, pady=10, side='bottom')

        button2 = tk.Button(self, text='Update',
                            command=lambda: deleteShiftFrame(self))
        button2.pack(padx=0, pady=10, side='bottom')

        text = tk.Label(self, text="All shifts", font=LARGEFONT)
        text.pack(padx=10, side='top')

        def deleteShiftFrame(self):
            table.destroy()
            viewNew(self)

        def viewNew(self):

            #frame to display shifts
            table = tk.Frame(self)
            table.pack(side='top', fill='both', expand=True)
            row = 0
            #make dictionary empty
            self.widgets = {}

            c.execute("SELECT * FROM shifts")
            data = c.fetchall()
            #create labels for each column
            date_label = tk.Label(table, text="Date")
            shift_label=tk.Label(table, text="Shift")
            shop_label=tk.Label(table, text="Shop")
            hours_label=tk.Label(table, text="Hours")

            #add labels to grid
            date_label.grid(row=0, column=0, sticky="nsw")
            shift_label.grid(row=0, column=1, sticky="nsw")
            shop_label.grid(row=0, column=2, sticky="nsw")
            hours_label.grid(row=0, column=3, sticky="nsw")

            #for each column create a tk label for each row within column with corresponding details

            for id, date, shift, shop, hours in (data):
                row+=1
                self.widgets[id] = {
                    "id":tk.Label(table, text=id),
                    "date":tk.Label(table, text=date),
                    "shift":tk.Label(table, text=shift),
                    "shop":tk.Label(table, text=shop),
                    "hours":tk.Label(table, text=hours)
                    }

                #add current row of column to grid
                self.widgets[id]["date"].grid(row=row, column=0, sticky="nsw")
                self.widgets[id]["shift"].grid(row=row, column=1, sticky="nsw")
                self.widgets[id]["shop"].grid(row=row, column=2, sticky="nsw")
                self.widgets[id]["hours"].grid(row=row, column=3, sticky="nsw")

                #add blank column between each field for spacing
                table.grid_columnconfigure(0, weight=1)
                table.grid_columnconfigure(1, weight=1)
                table.grid_columnconfigure(2, weight=1)
                table.grid_columnconfigure(3, weight=1)
                #add extra row for padding
                table.grid_rowconfigure(row+1, weight=1)

        viewNew(self)



class AddShifts(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        text = tk.Label(self, text = "Add shifts", font=LARGEFONT)
        text.pack(padx=10, side = 'top')

        #create frame for entry
        AddShiftFrame = tk.Frame(self)
        AddShiftFrame.pack(side="top", fill="both", expand=True)

        #add column headers
        dateLabel = tk.Label(AddShiftFrame, text="Date")
        shiftLabel = tk.Label(AddShiftFrame, text="Shift")
        shopLabel = tk.Label(AddShiftFrame, text='Shop')

        dateLabel.grid(row=1, column=0, sticky="nsw")
        shiftLabel.grid(row=1, column=1, sticky="nsw")
        shopLabel.grid(row=1, column=2, sticky="nsw")

        #create dictionary of widgets
        self.widgets = {
            "Date":tk.Entry(AddShiftFrame),
            "Shift":tk.Entry(AddShiftFrame),
            "Shop":tk.Entry(AddShiftFrame)
            }

        #add widgets to frame
        self.widgets["Date"].grid(row=2, column=0, sticky="nsw")
        self.widgets["Shift"].grid(row=2, column=1, sticky="nsw")
        self.widgets["Shop"].grid(row=2, column=2, sticky="nsw")

         #this method will submit the data (callback function)
        def submit_data(self):
            shift_data = [(self.widgets["Date"].get()), (self.widgets["Shift"].get()), (self.widgets["Shop"].get())]

            c.execute("INSERT INTO shifts (date, shift, shop) VALUES(?,?,?)", (shift_data[0], shift_data[1], shift_data[2]))
            conn.commit()
            print("done")

        #submit button
        submit = tk.Button(self, text="Submit",
                           command= lambda: submit_data(self))
        submit.pack(padx=10, pady=10, side="left")

        #home button
        button1 = tk.Button(self, text="Home",
                            command=lambda: controller.showFrame(StartPage))
        button1.pack(padx=10, pady=10, side='left')


app = MainApplication()
app.after(1000, getShifts)
app.mainloop()