Python Tkinter - 在菜单中添加外部函数作为命令

Question

I'm having a problem with Tkinter menu. Here is the code for my gui.py file:

from tkinter import *
from SS2 import file

class AppUI(Frame):

    def __init__(self, master=None):
        Frame.__init__(self, master, relief=SUNKEN, bd=2)

        self.menubar = Menu(self)

        menu = Menu(self.menubar, tearoff=0)
        self.menubar.add_cascade(label="File", menu=menu)
        menu.add_command(label="Open", command=file.open())
        menu.add_command(label="Save")
        menu.add_command(label="Save as...")
        menu.add_command(label="Exit",
                         command=root.quit)

        menu = Menu(self.menubar, tearoff=0)
        self.menubar.add_cascade(label="Image", menu=menu)
        menu.add_command(label="Size")
        menu.add_command(label="Rotate")
        menu.add_command(label="Crop")

        menu = Menu(self.menubar, tearoff=0)
        self.menubar.add_cascade(label="Color", menu=menu)

        menu = Menu(self.menubar, tearoff=0)
        self.menubar.add_cascade(label="Filter", menu=menu)
        menu.add_command(label="Blur")
        menu.add_command(label="Contour")
        menu.add_command(label="Emboss")
        menu.add_command(label="Smooth")
        menu.add_command(label="Sharpen")

        menu = Menu(self.menubar, tearoff=0)
        self.menubar.add_cascade(label="Help", menu=menu)
        menu.add_command(label="About")

        try:
            self.master.config(menu=self.menubar)
        except AttributeError:
            # master is a toplevel window (Python 1.4/Tkinter 1.63)
            self.master.tk.call(master, "config", "-menu", self.menubar)

        self.canvas = Canvas(self, bg="white", width=400, height=400,
                             bd=0, highlightthickness=0)
        self.canvas.pack()


root = Tk()

app = AppUI(root)
app.pack()

root.mainloop()

And here is the code for my file.py:

from tkinter import *
from tkinter.filedialog import askopenfilename

def open():
    filename = askopenfilename(filetypes=[("allfiles","*"),("imagesfiles","*.png")])

The problem is, when I run the gui.py file, the file dialogue always appears before the menu, and when I close it and try to access it through the menu Open, nothing happens. What did I do wrong here? Please help and thanks in advance.

Answer 1

Commands should give the name of the method. What you're doing is calling the method. Tkinter will then use the return value of that method as the button command. Solution: leave out the brackets.

..., command=file.open

instead of

..., command=file.open()

You did it right for the exit button though!