为什么小部件在 tkinter canvas 中堆叠在一起？
Why are the widgets stacked on top of each other in the tkinter canvas?
我一直在使用 tkinter 在 python 中创建一个程序，我有一个需要 滚动条 的下载选项卡。经过一些 google 搜索后，我发现要使完整的应用程序可滚动并不容易，因为只有几个小部件本机支持滚动条小部件。我搜索了它并找到了一种方法，但是，当我尝试自己实现它时，我遇到了一个错误。当我通过这种方法使用网格时，小部件会相互堆叠，而不是在单独的行中。我尝试像教程一样用 for 循环做同样的事情，问题解决了，但我不希望我的程序使用 for 循环。这是没有 for 循环的代码：
from tkinter import *
from tkinter import ttk
available_row = 0
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
global available_row
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# Configure the canvas
cnava.configure(yscrollcommand=my_scrollbar.set)
cnava.bind("<Configure>", lambda e: cnava.configure(scrollregion=cnava.bbox("all")))
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window((0, 0), window=second_frame, anchor="nw")
ttk.Button(second_frame, text=f"This is the {available_row}th button").grid(row=available_row, column=0)
available_row += 1
print(f"Next available row: {available_row}")
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
root.mainloop()
下面是带有 for 循环的相同代码：
from tkinter import *
from tkinter import ttk
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# Configure the canvas
cnava.configure(yscrollcommand=my_scrollbar.set)
cnava.bind("<Configure>", lambda e: cnava.configure(scrollregion=cnava.bbox("all")))
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window((0, 0), window=second_frame, anchor="nw")
# Creating a loop to grid 100 buttons
for i in range(100):
ttk.Button(second_frame, text=f"This is the {i}th button").grid(row=i, column=0)
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
root.mainloop()
好像在第一个程序中，canvas 也没有调整大小，因为红色区域没有变化，因此按钮相互重叠。我该如何解决这个问题？
您创建一个新的 second_frame 并在每次执行 pack_bars() 时将其放在 canvas 中的相同位置。您应该在函数外部创建 second_frame。
此外，您应该将 <Configure> 绑定到 second_frame 而不是 cnava。
以下是根据您的修改后的代码：
from tkinter import *
from tkinter import ttk
available_row = 0
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
global available_row
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# add a new button to second_frame
ttk.Button(second_frame, text=f"This is the {available_row}th button").grid(row=available_row, column=0)
available_row += 1
print(f"Next available row: {available_row}")
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
cnava.configure(yscrollcommand=my_scrollbar.set)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window(0, 0, window=second_frame, anchor='nw')
# update canvas scrollregion whenever the size of second_frame is changed
second_frame.bind('<Configure>', lambda e: cnava.configure(scrollregion=cnava.bbox('all')))
root.mainloop()
我一直在使用 tkinter 在 python 中创建一个程序，我有一个需要 滚动条 的下载选项卡。经过一些 google 搜索后，我发现要使完整的应用程序可滚动并不容易，因为只有几个小部件本机支持滚动条小部件。我搜索了它并找到了一种方法，但是，当我尝试自己实现它时，我遇到了一个错误。当我通过这种方法使用网格时，小部件会相互堆叠，而不是在单独的行中。我尝试像教程一样用 for 循环做同样的事情，问题解决了，但我不希望我的程序使用 for 循环。这是没有 for 循环的代码：
from tkinter import *
from tkinter import ttk
available_row = 0
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
global available_row
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# Configure the canvas
cnava.configure(yscrollcommand=my_scrollbar.set)
cnava.bind("<Configure>", lambda e: cnava.configure(scrollregion=cnava.bbox("all")))
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window((0, 0), window=second_frame, anchor="nw")
ttk.Button(second_frame, text=f"This is the {available_row}th button").grid(row=available_row, column=0)
available_row += 1
print(f"Next available row: {available_row}")
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
root.mainloop()
下面是带有 for 循环的相同代码：
from tkinter import *
from tkinter import ttk
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# Configure the canvas
cnava.configure(yscrollcommand=my_scrollbar.set)
cnava.bind("<Configure>", lambda e: cnava.configure(scrollregion=cnava.bbox("all")))
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window((0, 0), window=second_frame, anchor="nw")
# Creating a loop to grid 100 buttons
for i in range(100):
ttk.Button(second_frame, text=f"This is the {i}th button").grid(row=i, column=0)
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
root.mainloop()
好像在第一个程序中，canvas 也没有调整大小，因为红色区域没有变化，因此按钮相互重叠。我该如何解决这个问题？
您创建一个新的 second_frame 并在每次执行 pack_bars() 时将其放在 canvas 中的相同位置。您应该在函数外部创建 second_frame。
此外，您应该将 <Configure> 绑定到 second_frame 而不是 cnava。
以下是根据您的修改后的代码：
from tkinter import *
from tkinter import ttk
available_row = 0
root = Tk()
root.title("A Scrollbar")
root.geometry("580x308")
# Create a download frame
download_fr = Frame(root, width=580, height=308)
big_lbl = Label(download_fr, text="Just a BIG label. ", font=("Helvetica", "30", "bold"))
prg_br = ttk.Progressbar(download_fr, orient=HORIZONTAL, length=300, mode='indeterminate')
def pack_bars():
global available_row
big_lbl.pack_forget()
prg_br.pack_forget()
# Pack the Scrollbar
my_scrollbar.pack(side=RIGHT, fill=Y)
# add a new button to second_frame
ttk.Button(second_frame, text=f"This is the {available_row}th button").grid(row=available_row, column=0)
available_row += 1
print(f"Next available row: {available_row}")
btn = Button(download_fr, text="Pack progress bars. ", command=pack_bars)
# Create a canvas
cnava = Canvas(download_fr, bg="red")
# Create a Scrollbar
my_scrollbar = ttk.Scrollbar(download_fr, orient=VERTICAL, command=cnava.yview)
cnava.configure(yscrollcommand=my_scrollbar.set)
big_lbl.pack(pady=(85, 5))
prg_br.pack()
prg_br.start(5)
cnava.pack(side=LEFT, fill=BOTH, expand=1)
btn.pack()
download_fr.pack(fill=BOTH, expand=1)
# Create another frame inside the canvas
second_frame = Frame(cnava)
# Add that new frame to a window in the canvas
cnava.create_window(0, 0, window=second_frame, anchor='nw')
# update canvas scrollregion whenever the size of second_frame is changed
second_frame.bind('<Configure>', lambda e: cnava.configure(scrollregion=cnava.bbox('all')))
root.mainloop()