如何将python事件变量传递给另一个函数？

Question

我正在构建一个简单的 GUI，但在尝试将事件变量传递给另一个已经具有事件变量的函数时遇到了问题。

我正在尝试将变量“sqlItemx”（它是“self.item1”的事件变量）用于函数“addNumbs”。

如何传递此变量以供以后使用？

我尝试按照通常的约定简单地传递变量，但这对我不起作用。

我的代码摘录如下：

def listitems(self, event):
    for widget in self.itemFrame.winfo_children():
        widget.destroy()
    searchLettersx = event.widget['text']
    mycursor.execute("SELECT Name FROM inventory WHERE Name LIKE '" + searchLettersx + "%' ")
    myresult = mycursor.fetchall()
    rcount = 0
    ccount = 0
    for y in myresult:
        self.item1 = tk.Button(self.itemFrame, text=y, bg='white', fg='deep sky blue', font=("Helvetica", 18), height='4', width='22')
        self.item1.grid(column=ccount, row=rcount)
        self.item1.bind('<Button-1>', self.addtoCart)
        if rcount >= 5:
            ccount += 1
            rcount = 0
        rcount += 1  

 def addtoCart(self, event):
    win = tk.Toplevel(bg="white")
    win.wm_title("Add to Cart")

    sqlItemx = event.widget['text']

    frame = tk.Frame(win)
    frame.grid()
    self.numpadFrame = tk.Frame(win, pady='20', bg="white")
    self.numpadFrame.grid(column='0', row='2')

    itemLabel = tk.Label(win, text=sqlItemx, bg="white", font=("Helvetica", 18), pady="30")
    itemLabel.grid(row=0, column=0)

    numLabel = tk.Label(win, text="How many? ", bg="white", font=("Helvetica", 18), pady="30", anchor='e', justify='left')
    numLabel.grid(row=1, column=0)

    numbers = ["1", "2", "3", "4" , "5" , "6" , "7" , "8" , "9" , " " , "0" , " "]
    count = 0

    for r in range(4):
        for c in range(3):
            numpad = tk.Button(self.numpadFrame, text=numbers[count], height='4', width='8', bg='white', fg='deep sky blue', font=("Helvetica", 18))
            numpad.grid(row=r+1,column=c)
            numpad.bind('<Button-1>', self.addNumbs)
            count += 1

    finalize = tk.Button(win, text="Submit", height='2', width='14', bg='white', fg='deep sky blue', font=("Helvetica", 18))
    finalize.grid(column='0', row='7', columnspan='4')
    finalize["command"] = win.destroy

def addNumbs(self, event):

    numPadx = event.widget['text']

    sql = "INSERT INTO tempcart (item, count) VALUES (%s, %s)"
    val = ("item", numPadx)
    addtempCart.execute(sql, val)
    mydb.commit()

    gettempCartID.execute("SELECT ID FROM tempcart ORDER BY ID DESC LIMIT 1")
    gettempCartID_result = gettempCartID.fetchall()

    gettempCart.execute("SELECT item, count FROM tempcart")
    gettempCart_result = gettempCart.fetchall()

    for y in gettempCart_result:
        for z in gettempCartID_result: 
            self.cartItem = tk.Label(self.cartFrame, text=y, bg="white", font=("Helvetica", 20))
            self.cartItem.grid(column="0", row=z)

    mydb.commit()

我的最终目标是能够将此变量的值传递给“addNumbs”，并将其用作我的 MySQL 语句的变量“val”中的值。

Answer 1

您不需要通过bind 方法将命令附加到按钮；相反，您可以使用 command 关键字参数。

为了传递 item_type 参数，您需要遍历与创建的每个按钮对应的各种参数，并在创建按钮时将它们包含在函数调用中。..

可能是这样的：

...
list_of_items = [item0, item1, item2, ...]
item_buttons = []   # keep a reference on each button

for y, item in enumerate(list_of_items):
    btn = tk.Button(self.itemFrame, command=lambda item=item: self.addtoCart(item), ...)
    item_buttons.append(btn)
    btn.grid(column=ccount, row=rcount)
...