TixMessage data type

The TixMessage data type defines the data that are passed to the extension DLL's TixHandler entry point when the installer calls the extension DLL.

typedef struct TixMessage
    DWORD dwMessageID;
    DWORD dwReserved;
    DWORD dwSessionType;
    LONG lResult;
    LPARAM lCookie;
} TixMessage;

Data fields

Message identifier; see Extension DLL messages for a complete list.
Reserved for future use.
Session type identifier; see TIXSES_xxx for a complete list. The session type allows your extension DLL to decide if it needs to handle this particular message in the current session.
Result code if the message is handled; ignored otherwise. Applicable result codes depend on the message and should be chosen from the TIXRET_xxx definitions. As a special case, the result code for TIXMSG_GETVERSION must be the __TIXVER__ value that was in effect when the extension DLL was created.
Client-defined "cookie" that may be used to maintain additional client-specific state between messages. InstallMate sets this field to 0 prior to the first message and from then on maintains its value between messages. In a typical scenario, clients allocate some state information during the TIXMSG_INITIALIZE message, use it during subsequent messages, and release it during TIXMSG_TERMINATE.