[Accept drop file] #BCB

main.cpp

// .h
void __fastcall AcceptFiles (TMessage& Msg);

BEGIN_MESSAGE_MAP
    MESSAGE_HANDLER(WM_DROPFILES, TMessage, AcceptFiles)
END_MESSAGE_MAP(TForm)

// .cpp
__fastcall TFormMain::TFormMain(TComponent* Owner)
    : TForm(Owner)
{
    DragAcceptFiles(Handle, true);
}

//
void __fastcall TFormMain::AcceptFiles(TMessage& Msg)
{
    char path[MAX_PATH];
    // int count = DragQueryFile((HANDLE)Msg.WParam, 0xffffffff, path , MAX_PATH);
    DragQueryFile((HANDLE )Msg.WParam, 0, path , MAX_PATH);
    ShowMessage(path);
    DragFinish ((HANDLE)Msg.WParam);
}