kinter下拉菜单不收缩

Question

我试图在tkinter中创建一个应用程序，该应用程序有一个下拉菜单，允许多次选择。问题是，当我选择一个选项，菜单撤回，我必须重新打开它手动选择下一个选项。有没有办法让下拉菜单保持打开状态直到，比如，点击应用内外的某个地方或者直到我再次点击下拉菜单的顶部?

import tkinter as tk
def update_selected_options(option, var, selected_options):
    if var.get():
        selected_options.append(option)
    else:
        selected_options.remove(option)
    print(selected_options)
def select_option(option, var, selected_options):
    update_selected_options(option, var, selected_options)
def create_dropdown(parent, options):
    selected_options = []
    # create menubutton
    menubutton = tk.Menubutton(parent, text="Choose options", indicatoron=True, borderwidth=1, relief="raised")
    menu = tk.Menu(menubutton, tearoff=True)
    menubutton.configure(menu=menu)
    menubutton.pack(padx=10, pady=10)
    # add checkbuttons to menu
    for option in options:
        var = tk.BooleanVar(value=False)
        menu.add_checkbutton(label=option, variable=var, onvalue=True, offvalue=False, command=lambda option=option, var=var: select_option(option, var, selected_options))
    # keep menu open after an option is selected
    menu.postcommand = lambda: menubutton.config(state="active")
    return menubutton
if __name__ == "__main__":
    root = tk.Tk()
    options = ["Option 1", "Option 2", "Option 3"]
    menubutton = create_dropdown(root, options)
    root.mainloop()

我找到了这个menu.postcommand = lambda: menubutton.config(state="active")，但它似乎不能正确地完成工作

Answer 1

我对你的代码做了一些小的改变，但是解决你的问题的主线是menu.post(menubutton.winfo_rootx(), menubutton.winfo_rooty() + menubutton.winfo_height())。我从这个问题中得到的。基本上，每次调用select_option函数时，它都会在menubutton的位置重新打开drop-down menu。当你将+100添加到x或y坐标时，你就可以得到这个想法。

import tkinter as tk

def select_option(option, var):
global selected_options
if var.get():
selected_options.append(option)
else:
selected_options.remove(option)
print(selected_options)
menu.post(menubutton.winfo_rootx(), menubutton.winfo_rooty() + menubutton.winfo_height())

if __name__ == "__main__":
root = tk.Tk()
options = ["Option 1", "Option 2", "Option 3"]
selected_options = []
# create menubutton
menubutton = tk.Menubutton(root, text="Choose options", indicatoron=True, activeforeground='blue', highlightcolor='blue', borderwidth=1, relief="raised")
menu = tk.Menu(menubutton, tearoff=False, activeborderwidth=10, activeforeground='blue')
menubutton.configure(menu=menu)
menubutton.pack(padx=10, pady=10)
# add checkbuttons to menu
for option in options:
var = tk.BooleanVar(value=False)
menu.add_checkbutton(label=option, variable=var, onvalue=True, offvalue=False, command=lambda option=option, var=var: select_option(option, var))

root.mainloop()