python - 使用 tkinter 编辑文本时显示下拉组合框

Question

是否可以在打开下拉菜单时使组合框可编辑？我还没有找到任何解决方案。我想让它更像 Google 搜索，但使用 ComboBox。

Answer 1

Question: Show Combobox PopdownWindow, while editing text

这个例子扩展了一个 ttk.Combobox到以下内容:

• 在输入时显示 PopdownWindow
• 在按键 '<Down>' 上打开 PopdownWindow
• 在按下按键时关闭 PopdownWindow '<Up' , 如果在 Listbox 中的第一项

---

引用:

• Events and Bindings

  For each widget, you can bind Python functions and methods to events.

• ttk::combobox — text field with popdown selection list

  The ttk::combobox uses the entry and listbox widgets internally.

---

1. 继承自 ttk.Combox

   import tkinter as tk
   import tkinter.ttk as ttk
   
   
   class Combobox(ttk.Combobox):
   

2. 辅助函数，映射内部Toplevel和 Listbox到 tkinter目的。

   WARNING: This uses Tk/Tcl internals, which could change without notice.
   This may working only with the tested Tk/Tcl version!

   def _tk(self, cls, parent):
       obj = cls(parent)
       obj.destroy()
       if cls is tk.Toplevel:
           obj._w = self.tk.call('ttk::combobox::PopdownWindow', self)
       else:
           obj._w = '{}.{}'.format(parent._w, 'f.l')
       return obj
   

3. 初始化对象，获取内部引用并绑定(bind)到按键事件

   def __init__(self, parent, **kwargs):
       super().__init__(parent, **kwargs)
       self.popdown = self._tk(tk.Toplevel, parent)
       self.listbox = self._tk(tk.Listbox, self.popdown)
   
       self.bind("<KeyPress>", self.on_keypress, '+')
       self.listbox.bind("<Up>", self.on_keypress)
   

4. 用于显示或隐藏 PopdownWindow 并设置键盘焦点的按键处理程序。

   def on_keypress(self, event):
       if event.widget == self:
           state = self.popdown.state()
   
           if state == 'withdrawn' \
                   and event.keysym not in ['BackSpace', 'Up']:
               self.event_generate('<Button-1>')
               self.after(0, self.focus_set)
   
           if event.keysym == 'Down':
               self.after(0, self.listbox.focus_set)
   
       else:  # self.listbox
           curselection = self.listbox.curselection()
   
           if event.keysym == 'Up' and curselection[0] == 0:
               self.popdown.withdraw()
   
   

   Usage:

   class App(tk.Tk):
       def __init__(self):
           super().__init__()
   
           values = ('one', 'two', 'three', 'four', 'five', 'six', 'seven')
   
           self.cb = Combobox(self, value=values)
           self.cb.grid(row=0, column=0)
   
   
   if __name__ == "__main__":
       App().mainloop()
   
   

   使用 Python 测试:3.5 - 'TclVersion':8.6 'TkVersion':8.6