如下图，这种矩形选择框在图形软件里是必备操作，用python怎么实现？我用wxpython 做了一个例子。

 代码如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Project: test
# File   : SelectRectang.py
# Author : Long.Xu <fangkailove@yeah.net>
#          http://gnolux.blog.csdn.net
#          QQ:26564303 weixin:wxgnolux
# Time   : 2023/6/20 21:39
# Copyright 2023 Long.Xu All rights Reserved.

import wx


class MyFrame(wx.Frame):
    def __init__(self, parent, id, title, pos=wx.DefaultPosition,
                 size=(1200, 800), style=wx.DEFAULT_FRAME_STYLE):
        wx.Frame.__init__(self, parent, id, title, pos, size, style)
        self._dragstartpos = None
        self._dragendpos = None
        self.Bind(wx.EVT_PAINT,self.OnPaint)
        self.Bind(wx.EVT_MOUSE_EVENTS,self.OnMouseEvent)

    def OnPaint(self,evt):
        dc = wx.PaintDC(self)
        #self.PrepareDC(dc)
        dc.Clear()
        if  self._dragstartpos and self._dragendpos:
            font: wx.Font = dc.GetFont()
            x = min(self._dragendpos[0],self._dragstartpos[0])
            y = min(self._dragendpos[1],self._dragstartpos[1])
            w = abs(self._dragendpos[0]-self._dragstartpos[0])
            h = abs(self._dragendpos[1]-self._dragstartpos[1])
            pen = wx.Pen("red", 1, wx.PENSTYLE_USER_DASH)
            pen.SetDashes([10,10])
            dc.SetPen(pen)
            dc.SetBrush(wx.Brush("white", wx.BRUSHSTYLE_TRANSPARENT))
            # x,y=self.CalcUnscrolledPosition(x,y)
            text = "x:%d,y:%d,w:%d,h:%d" % (x,y,w,h)
            text_extent = self.GetFullTextExtent(text, font)
            dc.DrawText(text, x+(w - text_extent[0]) // 2, y+(h - text_extent[1]) // 2)
            dc.DrawRectangle(x,y,w,h)
        dc.EndDoc()

    def OnMouseEvent(self,event):
        if event.ButtonDown():
            if not self.HasCapture():
                self.CaptureMouse()
            self._dragstartpos = event.GetPosition()
            # print(self._dragstartpos)
            # self.FocusedMask.SetFocus()
        elif event.Dragging()  and self.HasCapture():
            pt = event.GetPosition()
            dx = pt[0] - self._dragstartpos[0]
            dy = pt[1] - self._dragstartpos[1]
            if event.LeftIsDown() and self._dragstartpos:
                self._dragendpos = event.GetPosition()
                self.Refresh()
        elif event.ButtonUp():
            if self.HasCapture():
                self.ReleaseMouse()
                if  event.LeftUp() and self._dragendpos and self._dragstartpos:
                    w = abs(self._dragstartpos[0]-self._dragendpos[0])
                    h = abs(self._dragstartpos[1]-self._dragendpos[1])
                    x = min(self._dragstartpos[0],self._dragendpos[0])
                    y = min(self._dragstartpos[1],self._dragendpos[1])
                    if w>8 and h>8:
                        print("selection:",x,y,w,h)
                self._dragstartpos = None
                self._dragendpos = None
                self.Refresh()

        event.Skip()




if __name__ == '__main__':
    app = wx.App()
    frm = MyFrame(None, -1, "wxPython 矩形选择框 测试")
    frm.Show()
    app.MainLoop()