Trying to Communicate with WinAmp

Question

Hi,
I am trying to communicate with WinAmp (MP3 player) through the sendmessage function in User32.dll
So far I can send commands like play, stop, forward, play next etc. but sending a filename to play gives no result.
This is the structure of the command: 
#define IPC_ENQUEUEFILE 100
/* This is sent as a WM_COPYDATA with IPC_PLAYFILE as the dwData member and the string
** of the file / playlist to be enqueued into the playlist editor as the lpData member.
** This will just enqueue the file or files since you can use this to enqueue a playlist.
** It will not clear the current playlist or change the playback state.
** COPYDATASTRUCT cds = {0};
**   cds.dwData = IPC_ENQUEUEFILE;
**   cds.lpData = (void*)"c:\\test\\folder\\test.mp3";
**   cds.cbData = lstrlen((char*)cds.lpData)+1;  // include space for null char
**   SendMessage(hwnd_winamp,WM_COPYDATA,0,(LPARAM)&cds);
WM_COPYDATA = 0x4A
In the VI you can see what I did. Before running the VI WinAmp must be already started. The led "windowfound" should be on.
I tried several things but no luck so far.
Can someone help me out with this problem ?
Solved!
Go to Solution.
Attachments:
WinAmp Test.vi ‏10 KB

Answer 1

Thank you for your priory information. I need to communicate with a C++ program using WM_COPYDATA. Since I need to send as well as receive data, I tried to write codes that send and receive WM_COPYDATA in LabVIEW. I think I succeeded to send WM_COPYDATA by following your example. However, I could not succeed in retrieving received COPYSTURCTURE data. Since I receive pointer I think I need to retrieve the data from the memory. I tried to use Moveblock, however, I failed.  I am attaching my example codes. Please take a look and give me comments.
Attachments:
smlib_WM_main.zip ‏29 KB