使用 tkinter 编辑文本时显示组合框下拉菜单 [英] Show combobox drop down while editing text using tkinter

问题描述

是否可以在打开下拉菜单时使 Combobox 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.

解决方案

问题:在编辑文本时显示Combobox PopdownWindow

此示例将 ttk.Combobox 扩展为以下内容:

• 键入时显示 PopdownWindow
• 按''
打开PopdownWindow
• 如果在 Listbox
中的第一项，则在按下按键 ' 时关闭 PopdownWindow

<小时>

参考:

• 事件和绑定

  <块引用>

  对于每个小部件，您可以将 Python 函数和方法绑定到事件.

• ttk::combobox — 带有弹出选择列表的文本字段

  <块引用>

  ttk::combobox 在内部使用 entry 和 listbox 小部件.

<小时>

1. 继承自ttk.Combox

   将 tkinter 导入为 tk将 tkinter.ttk 导入为 ttk类组合框(ttk.Combobox):

2. Helper 函数，将内部的 Toplevel 和 Listbox 映射到 tkinter 对象.

   <块引用>

   警告:这使用了 Tk/Tcl 内部结构，可能会发生更改，恕不另行通知.
   这可能仅适用于经过测试的 Tk/Tcl 版本！

   def _tk(self, cls, parent):obj = cls(父)obj.destroy()如果 cls 是 tk.Toplevel:obj._w = self.tk.call('ttk::combobox::PopdownWindow', self)别的:obj._w = '{}.{}'.format(parent._w, 'f.l')返回对象

3. 初始化对象，获取内部引用并绑定到按键事件

   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("", self.on_keypress, '+')self.listbox.bind("", 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):如果 event.widget == 自我:状态 = self.popdown.state()如果状态 == '撤回' 和 event.keysym 不在 ['BackSpace', 'Up'] 中:self.event_generate('')self.after(0, self.focus_set)如果 event.keysym == 'Down':self.after(0, self.listbox.focus_set)其他:# self.listboxcurselection = self.listbox.curselection()如果 event.keysym == 'Up' 和 curselection[0] == 0:self.popdown.withdraw()

   <块引用>

   用法:

   类应用程序(tk.Tk):def __init__(self):super().__init__()值 = ('一', '二', '三', '四', '五', '六', '七')self.cb = Combobox(self, value=values)self.cb.grid(row=0, column=0)如果 __name__ == "__main__":应用程序().主循环()

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

Is it possible to make Combobox editable while dropdown is opened? I haven't found any solution. I want to make it more like Google Search but using ComboBox.

解决方案

Question: Show Combobox PopdownWindow, while editing text

This example extends a ttk.Combobox to the following:

• Show the PopdownWindow while typing
• Open the PopdownWindow on Key-pressed '<Down>'
• Close the PopdownWindow on Key-pressed '<Up', if at the first item in the Listbox

---

Reference:

• 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. Inherit from ttk.Combox

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

2. Helper function, to map the internal Toplevel and Listbox to a tkinter object.

   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. Initalize the object, get the internal references and bind to Key-press events

   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. Key-pressed handler to show or hide the PopdownWindow and set the Keyboard focus.

   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()
   
   

   Tested with Python: 3.5 - 'TclVersion': 8.6 'TkVersion': 8.6

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