选择Listbox选项后在Text组件中显示光标异常问题

在Tkinter代码中，Listbox与Text组件配合时存在异常：选中Listbox的选项后，代码尝试将光标定位到Text组件的指定位置并获取焦点，但光标并未显示；只有按下Tab键手动激活Text组件后，光标才会正常出现。

对应的Listbox实现代码如下：

import tkinter as tk

list_cursor_pos = ['2.5', '5.10', '8.15']

def on_listbox_select(event):
    i = listbox.curselection()[0]
    cursor_pos = list_cursor_pos[i]

    text_box.focus_set()
    text_box.mark_set("insert", cursor_pos)
    text_box.see(cursor_pos)
    text_box.event_generate('<FocusIn>')
    
root = tk.Tk()

# Listbox
listbox = tk.Listbox(root)
listbox.pack(side = tk.LEFT, padx=10, pady=10)
for e in list_cursor_pos:
    listbox.insert('end', f'Go to {e} in the text')
listbox.bind("<<ListboxSelect>>", on_listbox_select)

# Text box
text_box = tk.Text(root, height=15, width=50)
text_box.pack(side = tk.RIGHT, padx=10, pady=10)
# Create content for text box
content = ""
for i in range(9):
    content += f"{i+1}:234567890123456789\n"
text_box.insert("1.0", content)

root.mainloop()

而改用Button组件实现相同的光标定位功能时，光标能够正常显示在Text组件中：

import tkinter as tk

def set_cursor_pos():
    cursor_pos = "2.5"
    text_box.focus_set()
    text_box.mark_set("insert", cursor_pos)

root = tk.Tk()

myButton = tk.Button(root, text = "Set cursor position at 2.5", command=set_cursor_pos)
myButton.pack(side = tk.LEFT, padx=10, pady=10)
myButton.focus_set()

# Text box
text_box = tk.Text(root, height=15, width=50)
text_box.pack(side = tk.RIGHT, padx=10, pady=10)
content = ""
for i in range(9):
    content += f"{i+1}:234567890123456789\n"
text_box.insert("1.0", content)

root.mainloop()

内容的提问来源于stack exchange，提问作者Daniel Louw