LINE_REPLY  1P8NRWN

The LINE_REPLY message is sent to report the results of function calls that completed asynchronously.

LINE_REPLY
    dwDevice = (DWORD) 0;

    dwCallbackInstance = (DWORD) hCallback;

    dwParam1 = (DWORD) idRequest;

    dwParam2 = (DWORD) Status;

    dwParam3 = (DWORD) 0;

Parameters

dwDevice

Not used.

dwCallbackInstance

Returns the application's callback instance.

dwParam1

The request ID for which this is the reply.

dwParam2

The success or error indication. The application should cast this parameter into a LONG. Zero indicates success; a negative number indicates an error.

dwParam3

Unused.

Return Values

No return value.

Remarks

Functions that operate asynchronously return a positive request ID value to the application. This request ID is returned with the reply message to identify the request that was completed. The other parameter for the LINE_REPLY message carries the success or failure indication. Possible errors are the same as those defined by the corresponding function. This message cannot be disabled.

In some cases, an application may fail to receive the LINE_REPLY message corresponding to a call to an asynchronous function. This occurs if the corresponding call handle is deallocated before the message has been received.