Tkinter：按钮和命令

问题描述

我正在创建一个生成随机歌曲列表的程序，我想执行一个函数，如果用户想要从随机生成的列表中保存一首歌曲，用户应该单击它旁边的按钮。似乎该函数只获取列表中的最后一首歌曲/元素。我该如何正确实施？我将如何防止在 alist 中出现相似或重复的歌曲？

这是代码：

 from tkinter import *
    import random
    a = [
        'Bruised and Scarred - Mayday Parade','All Too Well - Taylor Swift','Gravity - Sara Bareilles','Perfectly Perfect - Simple Plan','Welcome To The Black Parade - My Chemical Romance','Everything Has Changed - Taylor Swift','Champagne - Taylor Swift','Piece of Your Heart - Mayday Parade','blame It On The Rain - He Is We','Sad Song - We The Kings','Give It All - He Is We','Heavy - Linkin Park','Ride - Twenty One Pilot','One more light - Linkin Park','Ride Home - Ben and Ben','Leave - Ben and Ben','Fall - Ben and Ben','Maybe the night - Ben and Ben','Sunrise - Ben and Ben'
    ]

    
    root = Tk()
    root.title('GUI test')
    root.iconbitmap('icon2.ico')
    
    alist=[]
    
    
    def list_generator():
        for title in random.sample(a,k=10):
            myLabel = Label(frame,text=title,font='times 12',anchor=W)
            myLabel.grid(column=2,columnspan=2,sticky=W+E)
    
        for i in range(10):
            Button(frame,text=str(i + 1) + ".",border=5,padx=5,pady=5,command=lambda: alist.append(title)
                   ).grid(column=0,row=i)
    
    
    def list():
        print(alist)
    
    
    frame = LabelFrame(root,border=3,relief=GROOVE)
    frame.grid(row=1,column=0,padx=30,pady=20)
    
    
    myButton = Button(root,text="Generate Playlist?",padx=87,pady=20,command=list_generator,fg="white",bg="#c0c0c0",font=("Bold",16))
    myButton.grid(row=0,columnspan=3)
    
    exit_btn = Button(root,text='Exit Program',command=root.quit)
    exit_btn.grid(row=3,column=0)
    sl = Button(root,text='Your list',command=list)
    sl.grid(row=2,column=0)
    
    root.mainloop()

解决方法

• 您在 list_generator 中的第二个循环只能访问最新的 title 值，因此我删除了第二个循环并将代码移至第一个循环。
• 我将循环更改为使用 enumerate，以便我们可以获取索引（就像您在第二个循环中所做的那样）。
• 您绑定到按钮的 lambda 函数没有存储 title 的值，这会导致所有 lambda 使用相同的值，因此我将其添加为唯一的默认值lambda 函数。
• 您覆盖了不是 bueno 的内置关键字 list，我将其更改为 print_list。

---

来自@acw1668 的comment

• alist 在调用 list_generator 时没有被清除。
• myLabel.grid 缺少 row 参数。

---

最终代码：

from tkinter import *
import random
a = [
    'Bruised and Scarred - Mayday Parade','All Too Well - Taylor Swift','Gravity - Sara Bareilles','Perfectly Perfect - Simple Plan','Welcome To The Black Parade - My Chemical Romance','Everything Has Changed - Taylor Swift','Champagne - Taylor Swift','Piece of Your Heart - Mayday Parade','Blame It On The Rain - He Is We','Sad Song - We The Kings','Give It All - He Is We','Heavy - Linkin Park','Ride - Twenty One Pilot','One more light - Linkin Park','Ride Home - Ben and Ben','Leave - Ben and Ben','Fall - Ben and Ben','Maybe the night - Ben and Ben','Sunrise - Ben and Ben'
]


root = Tk()
root.title('GUI test')
root.iconbitmap('icon2.ico')

alist=[]


def list_generator():
    alist.clear()
    for i,title in enumerate(random.sample(a,k=10)):
        myLabel = Label(frame,text=title,font='times 12',anchor=W)
        myLabel.grid(column=2,columnspan=2,sticky=W+E,row=i)

        Button(frame,text=str(i + 1) + ".",border=5,padx=5,pady=5,command=lambda title=title: alist.append(title)
               ).grid(column=0,row=i)


def print_list():
    print(alist)


frame = LabelFrame(root,border=3,relief=GROOVE)
frame.grid(row=1,column=0,padx=30,pady=20)


myButton = Button(root,text="Generate Playlist?",padx=87,pady=20,command=list_generator,fg="white",bg="#c0c0c0",font=("Bold",16))
myButton.grid(row=0,columnspan=3)

exit_btn = Button(root,text='Exit Program',command=root.quit)
exit_btn.grid(row=3,column=0)
sl = Button(root,text='Your list',command=print_list)
sl.grid(row=2,column=0)

root.mainloop()