python-2.7 - 带有 LIKE 搜索的 Python Tkinter 自动完成组合框？

Question

我正在尝试使用预定义的值填充 Tkinter 组合框以供选择。它正在填充，我可以输入并获得建议。但是，为了做到这一点，我必须肯定知道前几个字符。如果我知道字符串中间或末尾的一些文本，它就没有用，因为组合框只进行 'LIKE%' 搜索而不是 '%LIKE%' 搜索。

预期输出(键入单词“Ceramic”会获取包含该字符串的所有名称。注意:这不是 Tkinter 屏幕截图):

这是我迄今为止对代码的改编，如果有人能建议如何修改 AutocompleteCombobox 类来进行 LIKE 搜索，那就太好了。

下面的工作代码，例如，具有值 "Cranberry"和 "Strawberry"，我的要求是输入 "berry"并获得两种水果的建议。

import Tkinter
import ttk
import sqlite3


class AutocompleteCombobox(ttk.Combobox):

        def set_completion_list(self, completion_list):
                """Use our completion list as our drop down selection menu, arrows move through menu."""
                self._completion_list = sorted(completion_list, key=str.lower) # Work with a sorted list
                self._hits = []
                self._hit_index = 0
                self.position = 0
                self.bind('<KeyRelease>', self.handle_keyrelease)
                self['values'] = self._completion_list  # Setup our popup menu

        def autocomplete(self, delta=0):
                """autocomplete the Combobox, delta may be 0/1/-1 to cycle through possible hits"""
                if delta: # need to delete selection otherwise we would fix the current position
                        self.delete(self.position, Tkinter.END)
                else: # set position to end so selection starts where textentry ended
                        self.position = len(self.get())
                # collect hits
                _hits = []
                for element in self._completion_list:
                        if element.lower().startswith(self.get().lower()): # Match case insensitively
                                _hits.append(element)
                # if we have a new hit list, keep this in mind
                if _hits != self._hits:
                        self._hit_index = 0
                        self._hits=_hits
                # only allow cycling if we are in a known hit list
                if _hits == self._hits and self._hits:
                        self._hit_index = (self._hit_index + delta) % len(self._hits)
                # now finally perform the auto completion
                if self._hits:
                        self.delete(0,Tkinter.END)
                        self.insert(0,self._hits[self._hit_index])
                        self.select_range(self.position,Tkinter.END)

        def handle_keyrelease(self, event):
                """event handler for the keyrelease event on this widget"""
                if event.keysym == "BackSpace":
                        self.delete(self.index(Tkinter.INSERT), Tkinter.END)
                        self.position = self.index(Tkinter.END)
                if event.keysym == "Left":
                        if self.position < self.index(Tkinter.END): # delete the selection
                                self.delete(self.position, Tkinter.END)
                        else:
                                self.position = self.position-1 # delete one character
                                self.delete(self.position, Tkinter.END)
                if event.keysym == "Right":
                        self.position = self.index(Tkinter.END) # go to end (no selection)
                if len(event.keysym) == 1:
                        self.autocomplete()
                # No need for up/down, we'll jump to the popup
                # list at the position of the autocompletion


def test(test_list):
        """Run a mini application to test the AutocompleteEntry Widget."""
        root = Tkinter.Tk(className='AutocompleteCombobox')

        combo = AutocompleteCombobox(root)
        combo.set_completion_list(test_list)
        combo.pack()
        combo.focus_set()
        # I used a tiling WM with no controls, added a shortcut to quit
        root.bind('<Control-Q>', lambda event=None: root.destroy())
        root.bind('<Control-q>', lambda event=None: root.destroy())
        root.mainloop()

if __name__ == '__main__':
        test_list = ('apple', 'banana', 'Cranberry', 'dogwood', 'alpha', 'Acorn', 'Anise', 'Strawberry' )
        test(test_list)

Answer 1

我怀疑你需要

 if self.get().lower() in element.lower():

而不是

 if element.lower().startswith(self.get().lower()):

获取数据，如 %LIKE%在数据库中

---

但是不知道效果好不好因为这个Combobox用建议替换文本，所以如果你输入 be然后找到 Cranberry并到位be你不能写ber .

也许你应该显示 Cranberry作为分隔(下拉)列表或弹出提示。

或者你可能不得不使用 string.find()突出显示 Cranberry 中的正确位置并继续输入 ber在正确的位置。

---

编辑: 示例如何使用 Entry和 Listbox显示过滤列表

在 listbox_update我添加了排序列表(比较小写字符串)

#!/usr/bin/env python3

import tkinter as tk

def on_keyrelease(event):
    
    # get text from entry
    value = event.widget.get()
    value = value.strip().lower()
    
    # get data from test_list
    if value == '':
        data = test_list
    else:
        data = []
        for item in test_list:
            if value in item.lower():
                data.append(item)                

    # update data in listbox
    listbox_update(data)
    
    
def listbox_update(data):
    # delete previous data
    listbox.delete(0, 'end')
    
    # sorting data 
    data = sorted(data, key=str.lower)

    # put new data
    for item in data:
        listbox.insert('end', item)


def on_select(event):
    # display element selected on list
    print('(event) previous:', event.widget.get('active'))
    print('(event)  current:', event.widget.get(event.widget.curselection()))
    print('---')


# --- main ---

test_list = ('apple', 'banana', 'Cranberry', 'dogwood', 'alpha', 'Acorn', 'Anise', 'Strawberry' )

root = tk.Tk()

entry = tk.Entry(root)
entry.pack()
entry.bind('<KeyRelease>', on_keyrelease)

listbox = tk.Listbox(root)
listbox.pack()
#listbox.bind('<Double-Button-1>', on_select)
listbox.bind('<<ListboxSelect>>', on_select)
listbox_update(test_list)

root.mainloop()

从完整列表开始

稍后仅使用过滤后的项目

---

编辑:2020.07.21

如果您想使用 <KeyPress>那么你必须改变 on_keyrelease并使用 event.char , event.keysym和/或 event.keycode因为KeyPress在 tkinter 之前执行更新 Entry 中的文本你必须添加event.char在 Entry 中发短信(或按 backspace 时删除最后一个字符)

if event.keysym == 'BackSpace':
    value = event.widget.get()[:-1]  # remove last char
else:
    value = event.widget.get() + event.char  # add new char at the end

可能需要对其他特殊键进行其他更改 Ctrl+A , Ctrl+X , Ctrl+C , Ctrl+E等，这会造成很大的问题。

#!/usr/bin/env python3

import tkinter as tk

def on_keypress(event):

    print(event)
    print(event.state & 4) # Control
    print(event.keysym == 'a')
    # get text from entry
    if event.keysym == 'BackSpace':
        # remove last char
        value = event.widget.get()[:-1]
    elif (event.state & 4): # and (event.keysym in ('a', 'c', 'x', 'e')):
        value = event.widget.get()
    else:
        # add new char at the end        
        value = event.widget.get() + event.char
    #TODO: other special keys

    value = value.strip().lower()

    # get data from test_list
    if value == '':
        data = test_list
    else:
        data = []
        for item in test_list:
            if value in item.lower():
                data.append(item)                

    # update data in listbox
    listbox_update(data)


def listbox_update(data):
    # delete previous data
    listbox.delete(0, 'end')

    # sorting data 
    data = sorted(data, key=str.lower)

    # put new data
    for item in data:
        listbox.insert('end', item)


def on_select(event):
    # display element selected on list
    print('(event) previous:', event.widget.get('active'))
    print('(event)  current:', event.widget.get(event.widget.curselection()))
    print('---')


# --- main ---

test_list = ('apple', 'banana', 'Cranberry', 'dogwood', 'alpha', 'Acorn', 'Anise', 'Strawberry' )

root = tk.Tk()

entry = tk.Entry(root)
entry.pack()
entry.bind('<KeyPress>', on_keypress)

listbox = tk.Listbox(root)
listbox.pack()
#listbox.bind('<Double-Button-1>', on_select)
listbox.bind('<<ListboxSelect>>', on_select)
listbox_update(test_list)

root.mainloop()

---

顺便说一句:

您也可以使用textvariable在 Entry与 StringVar和 trace在 StringVar 时执行函数改变内容。

var_text = tk.StringVar()
var_text.trace('w', on_change)

entry = tk.Entry(root, textvariable=var_text)
entry.pack()

---

#!/usr/bin/env python3

import tkinter as tk

def on_change(*args):
    #print(args)
          
    value = var_text.get()
    value = value.strip().lower()

    # get data from test_list
    if value == '':
        data = test_list
    else:
        data = []
        for item in test_list:
            if value in item.lower():
                data.append(item)                

    # update data in listbox
    listbox_update(data)


def listbox_update(data):
    # delete previous data
    listbox.delete(0, 'end')

    # sorting data 
    data = sorted(data, key=str.lower)

    # put new data
    for item in data:
        listbox.insert('end', item)


def on_select(event):
    # display element selected on list
    print('(event) previous:', event.widget.get('active'))
    print('(event)  current:', event.widget.get(event.widget.curselection()))
    print('---')

# --- main ---

test_list = ('apple', 'banana', 'Cranberry', 'dogwood', 'alpha', 'Acorn', 'Anise', 'Strawberry' )

root = tk.Tk()

var_text = tk.StringVar()
var_text.trace('w', on_change)

entry = tk.Entry(root, textvariable=var_text)
entry.pack()

listbox = tk.Listbox(root)
listbox.pack()
#listbox.bind('<Double-Button-1>', on_select)
listbox.bind('<<ListboxSelect>>', on_select)
listbox_update(test_list)

root.mainloop()