Question

我正在尝试创建一个小窗口，告诉我前十名玩家的资金。问题是，每当我点击更新按钮时，它都不会删除旧的播放器标签列表。 tkinter中有明确的功能吗？

CODE：

from tkinter import *
import sqlite3
def getlist():

    conn = sqlite3.connect('C:\sqlite\crapsdatabase.db')
    c = conn.cursor()

    c.execute("SELECT playerName, playerBank FROM player ORDER BY playerBank desc limit 10")
    temp = c.fetchall()
    for row in temp:
        texthold = str(row[0]) + ' ' + str(row[1])
        print(texthold)
        player = Label(root, text=texthold)
        player.pack()


    conn.commit() #confirms changes to the databae
    c.close() #closes the connection to the database
    conn.close()

root =Tk()

theLabel =Label(root, text="Top Ten Players")



buttonUpdate = Button(root, text="Update", fg="green", command = getlist)
buttonUpdate.pack()

theLabel.pack()
root.mainloop()

Answer 1

您应该使用Label方法，而不是创建新的player.config(text="Some new value")。（您需要在全局变量中保留对Label的引用。）

N.b。由于您有多个标签，因此应该在列表中保留对Label对象的引用。

Answer 2

由于getlist()正在为每个项目创建新的Label，因此一种方法是从窗口（和内存）中删除以前的列表，并生成一个新的播放器列表（和标签）

我们需要保留对已创建标签的引用（在getlist()中），以便稍后我们可以删除它们。像这样的代码（试图改变代码样本的最小值）：

from tkinter import *
import sqlite3

top_list = [] # holds the player labels currently shown

def getlist():
    global top_list

    conn = sqlite3.connect('C:\sqlite\crapsdatabase.db')
    c = conn.cursor()    
    c.execute("SELECT playerName, playerBank FROM player ORDER BY playerBank desc limit 10")
    temp = c.fetchall()

    for player in top_list:
        player.pack_forget() # remove label from window
    top_list = [] # remove references to free memory

    for row in temp:
        texthold = str(row[0]) + ' ' + str(row[1])
        print(texthold)
        player = Label(root, text=texthold)
        player.pack()
        top_list.append(player)

    conn.commit() #confirms changes to the databae
    c.close() #closes the connection to the database
    conn.close()

root = Tk()

theLabel = Label(root, text="Top Ten Players")
buttonUpdate = Button(root, text="Update", fg="green", command=getlist)
buttonUpdate.pack()

theLabel.pack()
root.mainloop()

如何在tkinter和python中刷新标签

2 个答案: