Python Tkinter如何从Listbox或按钮将选中值返回至列表

Tkinter中Button组件绑定的command回调函数的返回值会被框架默认丢弃，所以你现在直接在select_ingredients里return列表是没法在外部拿到的，可参考以下两种常用方案实现需求：

方案1：用外层可变容器存储结果（改动最小） #

直接在全局作用域定义一个可变容器（比如列表）存储选中结果，回调函数里直接修改这个容器的内容，后续其他代码可以直接读取该容器拿到选中列表，修改后的代码如下：

from tkinter import *
    
root = Tk()
root.title("blabla")
root.geometry("600x650")

# 定义全局列表存储选中的食材
selected_ingredients = []

Label(text="", width=15).grid(row=0, column=0)
Label(text="选择食材:", width=15).grid(row=1, column=0)
ingredients_listbox = Listbox(root, width=20, height=10, selectmode=MULTIPLE)
ingredients_listbox.grid(row=2, column=0)

# 给列表框添加垂直滚动条
ingredients_scroll = Scrollbar(command=ingredients_listbox.yview, orient=VERTICAL)
ingredients_scroll.grid(row=2, column=1, sticky='ns')
ingredients_listbox.configure(yscrollcommand=ingredients_scroll.set)


ingredients_list = ["无","茄子","红甜椒","番茄","洋葱","大蒜","香菜",
                    "西葫芦","洋蓟","蘑菇","橄榄","欧芹","花菜"]
for item in ingredients_list:
    ingredients_listbox.insert(END, item)

def select_ingredients():
    global selected_ingredients
    # 清空上一次的选中结果
    selected_ingredients.clear()
    for idx in ingredients_listbox.curselection():
       selected_ingredients.append(ingredients_listbox.get(idx))
    print("当前选中食材：", selected_ingredients)

ingredients_button = Button(root, text = "添加食材", command = select_ingredients).grid(row=3, column=0)

# 示例：其他位置直接读取selected_ingredients即可使用选中列表
def check_result():
    print("外部读取到的选中列表：", selected_ingredients)
Button(root, text="测试读取选中结果", command=check_result).grid(row=4, column=0)

root.mainloop()

方案2：类封装GUI（适合复杂项目） #

如果你的GUI功能比较复杂，更推荐用类封装所有组件和状态，避免全局变量污染，示例如下：

from tkinter import *

class IngredientSelector:
    def __init__(self, root):
        self.root = root
        self.root.title("blabla")
        self.root.geometry("600x650")
        # 实例属性存储选中结果
        self.selected_ingredients = []
        
        Label(text="", width=15).grid(row=0, column=0)
        Label(text="选择食材:", width=15).grid(row=1, column=0)
        self.ingredients_listbox = Listbox(root, width=20, height=10, selectmode=MULTIPLE)
        self.ingredients_listbox.grid(row=2, column=0)
        
        ingredients_scroll = Scrollbar(command=self.ingredients_listbox.yview, orient=VERTICAL)
        ingredients_scroll.grid(row=2, column=1, sticky='ns')
        self.ingredients_listbox.configure(yscrollcommand=ingredients_scroll.set)
        
        ingredients_list = ["无","茄子","红甜椒","番茄","洋葱","大蒜","香菜",
                            "西葫芦","洋蓟","蘑菇","橄榄","欧芹","花菜"]
        for item in ingredients_list:
            self.ingredients_listbox.insert(END, item)
        
        Button(root, text = "添加食材", command = self.select_ingredients).grid(row=3, column=0)
        Button(root, text="测试读取选中结果", command=self.check_result).grid(row=4, column=0)
    
    def select_ingredients(self):
        self.selected_ingredients.clear()
        for idx in self.ingredients_listbox.curselection():
            self.selected_ingredients.append(self.ingredients_listbox.get(idx))
        print("当前选中食材：", self.selected_ingredients)
    
    def check_result(self):
        print("外部读取到的选中列表：", self.selected_ingredients)

if __name__ == "__main__":
    root = Tk()
    app = IngredientSelector(root)
    root.mainloop()

两种方案都可以拿到选中的列表，你可以根据自己项目的复杂度选择对应的实现方式。

内容的提问来源于stack exchange，提问作者נועה בינסקי