Answer a Call Tutorial

This tutorial describes how to detect and answer an inbound call with the telephony API for applications.

1. 
   create a new instance of CTelephony
2. 
   Use CTelephony::NotifyChange() to detect changes in the voice line's status. NotifyChange() can be used to detect a variety of changes, but in this case you are only interested in the status of the voice line. Pass a notification event, in this case CTelephony::EVoiceLineStatusChange . Also pass it an empty CTelephony::TCallStatusV1Pckg . Possible status values are Idle, Ringing, On-Hold. When the voice line status is Ringing( CTelephony::EStatusRinging ) there is an incoming voice call to be answered.
3. 
   answer a call with CTelephony::AnswerIncomingCall() . You can only answer a call when the voice line status is Ringing( CTelephony::EStatusRinging )
4. 
   pass the enumeration CTelephony::EAnswerIncomingCallCancel to cancel the operation.

       
        
       
       #include <e32base.h>
#include <Etel3rdParty.h>

class CClientApp : public CActive
    { 

private:
    CTelephony* iTelephony;
    CTelephony::TCallId iCallId;

public:
    CClientApp(CTelephony* aTelephony);
    void SomeFunction();

private:
    /*
       These are the pure virtual methods from CActive that  
       MUST be implemented by all active objects
       */
    void RunL();
    void DoCancel();
   };

CClientApp::CClientApp(CTelephony* aTelephony)
    : CActive(EPriorityStandard),
      iTelephony(aTelephony)
    {
    //default constructor
    }

void CClientApp::SomeFunction()
    {
    iTelephony->AnswerIncomingCall(iStatus, iCallId);
    SetActive();
    }

void CClientApp::RunL()
    {
    if(iStatus==KErrNone)
       {} // The call has been answered successfully;
          // iCallId contains the call's ID, needed when controlling the call.
    }

void CClientApp::DoCancel()
    {
    iTelephony->CancelAsync(CTelephony::EAnswerIncomingCallCancel);
    }