>>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 )
>	
>

When you saying "length is 12 bytes", what you mean?

Thank you,