>Hi All,
>
>I have to use Sendmessage Winapi and receive message from opposite application. I found this code from internet:
>
>
>
>

>Declare Long FindWindowA In Win32API String cNULL, String cWinName
>DECLARE LONG SendMessage IN user32 AS WinAPI_SendMessage ; 
>	LONG,; 
>	LONG,; 
>	LONG,; 
>	STRING @
>sTitle = "kl_ecrsunucu"
>iHwnd = FindWindowA(0, sTitle)
>#DEFINE WM_COPYDATA 	0x004A
>*  _vfp.hWnd
>xstr="qqq"
>lnRetVal = WinAPI_SendMessage(ihWnd, WM_COPYDATA, this.HWnd , @xstr)
>WAIT WINDOW lnretval 
>

>
>opposite application look for kl_ecrclient caption at my form. What I should do for receive message after change my forms caption? How can I read message from opposite?

Metin,

If you use COPYDATA, then
the string ( xstr ) must respect the format - length is 12 bytes

typedef struct tagCOPYDATASTRUCT {
  ULONG_PTR dwData;	&& any data: The data to be passed to the receiving application
  DWORD     cbData; && The size, in bytes, of the data pointed to by the lpData member
  PVOID     lpData; && The data to be passed to the receiving application. This member can be NULL.	
} COPYDATASTRUCT, *PCOPYDATASTRUCT;

dwData : see above
cbData: see above
lpData: since this is a pointer to the data (ie the address, you have to allocate this space with an api - eg HeapAlloc(). Do not forget to free the buffer on exit : HeapFree)

Sending:

You can copy data to the allocated lpdata buffer with sys(2600)

Receive:

function ReceiveDetailMessage(hwnd, msg, wparam, lparam)

	local dwdata, cbdata , lpData, s
		
	dwdata = ctobin(Sys(2600, m.lparam+0, 4), '4rs')
	cbdata = ctobin(Sys(2600, m.lparam+4, 4), '4rs')
	lpData = ctobin(Sys(2600, m.lparam+8, 4), '4rs')
	s= sys(2600, m.lpData, m.cbdata )