Identifying Incoming Calls (Windows Embedded CE 6.0)
1/6/2010
TAPI 2.0 can identify the media mode of an incoming call.
The application calls the lineGetCallInfo function to determine the media modes.
For example, when a call comes in, a dialog box could identify the caller and let the application or the user decide whether to accept the call or send it over to voice mail.
The telephone company sends Caller ID information between the first and the second ring. The application can call the lineGetCallInfo function to obtain the data that is sent.
The LINECALLINFO structure contains relatively fixed information about a call. This structure is returned with the lineGetCallInfo function. When information items in this data structure have changed, a LINE_CALLINFO message is sent to the application. A parameter to this message is the information item or field that changed.
The LINE_CALLSTATE message informs applications that a call is arriving. This message provides the call handle, the privilege of the application to the call, and the new state of the call. For an unanswered incoming call, the call state is offering. An application can invoke the lineGetCallInfo function to obtain information about an offering call before it accepts it. This function call also causes the call information in the LINECALLINFO structure to be updated. By knowing the call state and other information, the application can determine whether the call must be answered.