How to use win32gui or similar, to click an other window toolStrip1 item button through its button name?

Question

In Python2.7 with win32, I can easily get other window's toolStrip1 handle through win32gui.EnumChildWindows, however I do not know how to get it's button item control through it's item name, e.g click item button "Load" in toolStrip1.

Can I try to use win32gui.SendMessage(handle, click, "Load"......) or a similar way to achieve this?

I can use rect x,y of toolStrip1 via win32gui.GetWindowRect, and roughly can do click button via x+40, x+80 accordingly, but it is not really good specially when the item position changes in the new version.

Here is the code from a sample and modified with a few other issues:

import win32con import commctrl, ctypes from ctypes import * import sys import time

class TextBox:

# represent the TBBUTTON structure

# note this is 32 bit, 64 bit padds 4 more reserved bytes

class TBBUTTON(Structure):
    _pack_ = 1
    _fields_ = [
        ('iBitmap', c_int),
        ('idCommand', c_int),
        ('fsState', c_ubyte),
        ('fsStyle', c_ubyte),
        ('bReserved', c_ubyte * 2),
        ('dwData', c_ulong),
        ('iString', c_int),
    ]

class RECT(Structure):
    _pack_ = 1
    _fields_ = [ 
        ('left',c_ulong),
        ('top',c_ulong),
        ('right',c_ulong),
        ('bottom',c_ulong),
    ]

def run(self):
    #init vars
    self.count=0

    #get the TestApp window
    lhWnd = win32gui.FindWindow(None,'TestApp')
    print "TestApp handle=",lhWnd

    #get the TestApp child window
    win32gui.EnumChildWindows(lhWnd, self.EnumChildWindows, 0)
    print "toolStrip1 handle=",self.toolbar_hwnd

    #focus TestApp window
    ctypes.windll.user32.SetFocus(lhWnd)
    win32gui.SetForegroundWindow(lhWnd)
    win32gui.ShowWindow(lhWnd, win32con.SW_SHOWNORMAL)


    #############################################donot work part####################################################        
    #to get how many item buttons in toolStrip1, it return 0  -- WHY?   <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    cnt = windll.user32.SendMessageA(self.toolbar_hwnd, commctrl.TB_BUTTONCOUNT, 0, 0)
    print "Why button cnt=0?? cnt=",cnt

    #and seems this is no affection as well -- Why?  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    index=1 #assume we got Load button index from it's name (do not know how?, Load Button index=1 based on 0
    win32api.PostMessage(self.toolbar_hwnd,commctrl.TCM_SETCURFOCUS,index,0) #TCM_SETCURSEL
    print "Why?? cannot focus on [Load] Button"
    time.sleep(3)

    #try to get [Load] button's rect, but not work  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<      
    pid = c_ulong();
    windll.user32.GetWindowThreadProcessId(self.toolbar_hwnd, byref(pid))
    hProcess = windll.kernel32.OpenProcess(win32con.PROCESS_ALL_ACCESS, 0, pid)
    lpPointer = windll.kernel32.VirtualAllocEx(hProcess, 0, sizeof(TBBUTTON), win32con.MEM_COMMIT, win32con.PAGE_READWRITE)
    rlpPointer = windll.kernel32.VirtualAllocEx(hProcess, 0, sizeof(RECT), win32con.MEM_COMMIT, win32con.PAGE_READWRITE)

    # init our tool bar button and a handle to it
    tbButton = TBBUTTON()
    butHandle = c_int()
    idx_rect = RECT()

    # query the button into the memory we allocated
    windll.user32.SendMessageA(self.toolbar_hwnd, commctrl.TB_GETBUTTON, index, lpPointer)
    # read the memory into our button struct
    windll.kernel32.ReadProcessMemory(hProcess, lpPointer, addressof(tbButton), 20, None)
    # read the 1st 4 bytes from the dwData into the butHandle var
    # these first 4 bytes contain the handle to the button
    windll.kernel32.ReadProcessMemory(hProcess, tbButton.dwData, addressof(butHandle), 4, None)

    # get the pid that created the button
    butPid = c_ulong()
    windll.user32.GetWindowThreadProcessId(butHandle, byref(butPid))

    wszBuff = create_unicode_buffer(win32con.MAX_PATH)
    windll.kernel32.ReadProcessMemory(hProcess, tbButton.iString, wszBuff, win32con.MAX_PATH, None)

    win32api.SendMessage(self.toolbar_hwnd,commctrl.TB_GETRECT,tbButton.idCommand,rlpPointer)
    windll.kernel32.ReadProcessMemory(hProcess, rlpPointer, addressof(idx_rect), sizeof(idx_rect), None)
    xpos = int((idx_rect.right-idx_rect.left)/2)+idx_rect.left
    ypos = int((idx_rect.bottom-idx_rect.top)/2)+idx_rect.top
    lParam = ypos<<16 | xpos
    print "Why x,y=0?? [Load] button X,Y=",xpos,ypos
    ###############################################################################################################

    #but assume we got button [Load] Rect[10,80] based on toolStrip1, and click it WORKS!
    lParam = 10<<16 | 80
    win32api.PostMessage(self.toolbar_hwnd,win32con.WM_LBUTTONDOWN,win32con.MK_LBUTTON,lParam)
    win32api.PostMessage(self.toolbar_hwnd,win32con.WM_LBUTTONUP,win32con.MK_LBUTTON,lParam)


def EnumChildWindows(self,lhWnd,lParam):
    text = win32gui.GetWindowText(lhWnd)
    #rect1 = win32gui.GetWindowRect(lhWnd)
    if text=="toolStrip1":
        self.toolbar_hwnd=lhWnd

rx=TextBox()

rx.run()