在按钮按下 tkinter 上制作新标签时出现问题

Question

    import tkinter as tk

root = tk.Tk()
root.title("To Do")
root.geometry("500x750")
root.resizable(False, False)

class App:
    def __init__(self, window):
        #Button font
        self.buttonFont = ("Courier", 13, "normal")
        #Header
        self.header = tk.Label(text = "To Do List\n", font = ("Helvetica", 26, "bold"))
        self.header.grid()
        #Add item button
        self.addButton = tk.Button(text = "Add Item", font = self.buttonFont, bg = "green", command = self.OpenAddItem)
        self.addButton.grid(row = 1, column = 0, )
        #Del item button
        self.delButton = tk.Button(text = "Delete Item", font = self.buttonFont, bg = "red")
        self.delButton.grid(row = 1, column = 1, )
        #items frame and stuff
        self.itemsframe = tk.Frame()
        self.itemsframe.grid(row = 2)
        self.item = tk.Label(self.itemsframe, font = ("Helvetica", 11, "normal"))
    def OpenAddItem(self):
        #COnfiguring prompt win
        self.addPromptWin = tk.Toplevel(root)
        self.addPromptWin.title("Prompt")
        self.addPromptWin.geometry("375x100")
        self.addPromptWin.resizable(False,False)
        #Entry label
        self.entryLabel = tk.Label(self.addPromptWin,text = "Enter item name:", font = ("Courier", 11, "normal"))
        self.entryLabel.grid(sticky = tk.E)
        #Adding entry 
        self.entry = tk.Entry(self.addPromptWin, font = ("Courier", 11, "normal"))
        self.entry.grid(row = 0, column = 1)
        self.entry.bind("<Return>", lambda e: self.AddItem())
        #Add new item button
        self.addNewItemButton = tk.Button(self.addPromptWin, text = "Add", font = self.buttonFont, bg = "green", command = self.AddItem)
        self.addNewItemButton.grid(row = 1, sticky = tk.W)
        
    def AddItem(self):
        self.entryValue = self.entry.get()
        
        self.item.config(text = f"1.  {self.entryValue}")
        self.item.pack()
        self.addPromptWin.destroy()

app = App(root) 
root.mainloop()

大家好，我的 tkinter gui 程序有问题。当我调用 addItem 函数时，不是每次都创建一个新标签，而是替换当前标签。任何帮助将不胜感激！

Answer 1

您创建了一个名为 self.item 的 Label，然后您不断覆盖它，期望它神奇地成为一个新的 Label。修复很简单~不要创建 self.item。相反，创建一个列表并在需要时将新的 Labels 推到它上面。这也为您的删除方法奠定了基础，因为您可以解压缓存中的所有内容，删除所需的项目并重新打包缓存中剩余的任何内容。我的示例在重要的地方进行了注释。我没有给你写删除方法。

import tkinter as tk

root = tk.Tk()
root.title("To Do")
root.geometry("500x750")
root.resizable(False, False)

class App:
    def __init__(self, window):
        #Button font
        self.buttonFont = ("Courier", 13, "normal")
        #Header
        self.header = tk.Label(text = "To Do List\n", font = ("Helvetica", 26, "bold"))
        self.header.grid()
        #Add item button
        self.addButton = tk.Button(text = "Add Item", font = self.buttonFont, bg = "green", command = self.OpenAddItem)
        self.addButton.grid(row = 1, column = 0, )
        #Del item button
        self.delButton = tk.Button(text = "Delete Item", font = self.buttonFont, bg = "red")
        self.delButton.grid(row = 1, column = 1, )
        #items frame and stuff
        self.itemsframe = tk.Frame()
        self.itemsframe.grid(row = 2)
        
        ''' you just keep overwriting this '''
        #self.item = tk.Label(self.itemsframe, font = ("Helvetica", 11, "normal"))
        
        #start a cache instead
        self.items = []
        
    def OpenAddItem(self):
        #COnfiguring prompt win
        self.addPromptWin = tk.Toplevel(root)
        self.addPromptWin.title("Prompt")
        self.addPromptWin.geometry("375x100")
        self.addPromptWin.resizable(False,False)
        #Entry label
        self.entryLabel = tk.Label(self.addPromptWin,text = "Enter item name:", font = ("Courier", 11, "normal"))
        self.entryLabel.grid(sticky = tk.E)
        #Adding entry 
        self.entry = tk.Entry(self.addPromptWin, font = ("Courier", 11, "normal"))
        self.entry.grid(row = 0, column = 1)
        self.entry.bind("<Return>", lambda e: self.AddItem())
        #Add new item button
        self.addNewItemButton = tk.Button(self.addPromptWin, text = "Add", font = self.buttonFont, bg = "green", command = self.AddItem)
        self.addNewItemButton.grid(row = 1, sticky = tk.W)
        
    def AddItem(self):
        self.entryValue = self.entry.get()
        
        '''
            you can keep configuring and repacking this for infinity
            it's not going to change the fact that it's the same label every time
        '''
        #self.item.config(text = f"1.  {self.entryValue}")
        #self.item.pack()
        
        #append a new label to the cache instead
        self.items.append(tk.Label(self.itemsframe, font = ("Helvetica", 11, "normal"), anchor='w'))
        
        #config and pack the last item in the cache
        self.items[-1].config(text = f"{len(self.items)}.  {self.entryValue}",)
        self.items[-1].pack(anchor='w')
        
        self.addPromptWin.destroy()

app = App(root) 
root.mainloop()

在按钮按下 tkinter 上制作新标签时出现问题

Issue when making new label on button press tkinter

python

tkinter

python-3.x

tkinter-entry