🚀 go-pugleaf

"Boba" <Boba@somewhere.world> wrote:

>COPYDATASTRUCT cds;
>cds.dwData=1;//number of strings to be sent

You are misusing the COPYDATASTRUCT structure.  You should not be using the dwData value that way.  Yes, it is an arbitrary 32-bit application-defined value - however - it is commonly used as a unique identifer instead.  WM_COPYDATA is so commonly used, even by the VCL itself, that you should assign your own unique value to dwData to help differentiate between your own WM_COPYDATA messages and those that are actually meant for other windows, which you should ignore.  If you need to specify how many strings are in the data, then you should allocate some extra memory and put the count inside the data itself instead of in the dwData value.

>cds.cbData=AnsiStringToSend.Length();//<1024
>cds.lpData=AnsiStringToSend.c_str();
>::SendMessage(hWndOfReceiver,WM_COPYDATA, 0,(LPARAM)&cds);

The only way that code can fail is if the source AnsiString is not valid to begin with, or if it is being altered between the time c_str() is called and WM_COPYDATA is sent.

>char buff[1024];
>::ZeroMemory(buff,sizeof(buff));
>::CopyMemory(buff,Msg.CopyDataStruct->lpData,Msg.CopyDataStruct->cbData);

You don't need a temporary buffer.  You can read into AnsiString directly, ie:

    AnsiString s;
    s.SetLength(Msg.CopyDataStruct->cbData);
    ::CopyMemory(s.c_str(), Msg.CopyDataStruct->lpData, Msg.CopyDataStruct->cbData);

Alternatively:

    AnsiString s((char*)Msg.CopyDataStruct->lpData, Msg.CopyDataStruct->cbData);


Gambit