动态滚动条tkinter

Question

我对tkinter还很陌生，所以我决定尝试制作一个简单的剽窃discord应用程序，当发送新消息时我遇到了麻烦。所以，当消息开始从页面上消失时，直到你发送另一条消息，才能看到最近的消息，我不知道为什么会这样。有人有什么想法吗？代码：

from tkinter import *
import tkinter.simpledialog
from tkinter import ttk
import tkinter as tk
import os


root = Tk()
root.title("discord rip off")
root.geometry("720x480+0+0")
def add_Server():
return tk.simpledialog.askinteger("Add Server", "Server Code")

# main message area
frame = Frame(root, width=600, height=300, bd=5, relief=RIDGE, bg="red") # the bd and the relief makes a nice effect outlineing the frame 
frame.grid(row=0, column=1)

messageEnter = Entry(frame)
messageEnter.pack(side=BOTTOM, fill=BOTH)
# canvas
myCanvas = Canvas(frame)
myCanvas.pack(fill=BOTH, side=LEFT)
# message scrollbar
messageScrollbar = ttk.Scrollbar(frame, orient=VERTICAL, command=myCanvas.yview)
messageScrollbar.pack(side=RIGHT, fill=Y)


# canvas
myCanvas.configure(yscrollcommand=messageScrollbar.set)
myCanvas.bind("<Configure>", lambda e: myCanvas.configure(scrollregion=(myCanvas.bbox("all"))))

# creating a second frame that is the message frame
messageFrame = Frame(myCanvas)
# canvas
myCanvas.create_window((0,0), window=messageFrame, anchor="nw")
def send_Message(event):
if messageEnter.get() == "":
print(myCanvas.bbox("all"))
pass
else:
Label(messageFrame, text=messageEnter.get(), anchor="w").pack(fill=X, expand=1)
myCanvas.configure(scrollregion=(myCanvas.bbox("all")))
messageEnter.delete(0, "end")
myCanvas.yview_moveto("1.0") # moves the scroll bar to the bottom when called

# send message
messageEnter.bind("<Return>", send_Message)

# server list
# photo = PhotoImage(file=os.path.dirname(__file__)+"/images/add.png")
# photo = photo.subsample(1, 1) # resizies image
serverListFrame = Frame(root, width=38, height=200, bg="blue")
serverListFrame.grid(row=0, column=0, sticky=N)

addServer = Button(root) # , image=photo
addServer.grid(row=0, column=0, sticky=N)
root.update()
root.mainloop()

谢谢。

Answer 1

"您必须重置Canvas的滚动区域以使新添加的Label可见-您正在这样做，但有点太早：Label还没有实际分配任何大小或位置(这需要主循环的迭代(，因此没有将其考虑在内。在创建标签和设置滚动区域之间放置root.update_idletasks((应该可以修复它；@jasonharper