Question:
How can I use TAPI to dial the telephone for a voice call?
Answer:
The following example shows how to interface with tapi to make a
voice call.
Example:
{tapi Errors}
const TAPIERR_CONNECTED = 0;
const TAPIERR_DROPPED = -1;
const TAPIERR_NOREQUESTRECIPIENT = -2;
const TAPIERR_REQUESTQUEUEFULL = -3;
const TAPIERR_INVALDESTADDRESS = -4;
const TAPIERR_INVALWINDOWHANDLE = -5;
const TAPIERR_INVALDEVICECLASS = -6;
const TAPIERR_INVALDEVICEID = -7;
const TAPIERR_DEVICECLASSUNAVAIL = -8;
const TAPIERR_DEVICEIDUNAVAIL = -9;
const TAPIERR_DEVICEINUSE = -10;
const TAPIERR_DESTBUSY = -11;
const TAPIERR_DESTNOANSWER = -12;
const TAPIERR_DESTUNAVAIL = -13;
const TAPIERR_UNKNOWNWINHANDLE = -14;
const TAPIERR_UNKNOWNREQUESTID = -15;
const TAPIERR_REQUESTFAILED = -16;
const TAPIERR_REQUESTCANCELLED = -17;
const TAPIERR_INVALPOINTER = -18;
{tapi size constants}
const TAPIMAXDESTADDRESSSIZE = 80;
const TAPIMAXAPPNAMESIZE = 40;
const TAPIMAXCALLEDPARTYSIZE = 40;
const TAPIMAXCOMMENTSIZE = 80;
const TAPIMAXDEVICECLASSSIZE = 40;
const TAPIMAXDEVICEIDSIZE = 40;
function tapiRequestMakeCallA(DestAddress : PAnsiChar;
AppName : PAnsiChar;
CalledParty : PAnsiChar;
Comment : PAnsiChar) : LongInt;
stdcall; external 'TAPI32.DLL';
function tapiRequestMakeCallW(DestAddress : PWideChar;
AppName : PWideChar;
CalledParty : PWideChar;
Comment : PWideChar) : LongInt;
stdcall; external 'TAPI32.DLL';
function tapiRequestMakeCall(DestAddress : PChar;
AppName : PChar;
CalledParty : PChar;
Comment : PChar) : LongInt;
stdcall; external 'TAPI32.DLL';
procedure TForm1.Button1Click(Sender: TObject);
var
DestAddress : string;
CalledParty : string;
Comment : string;
begin
DestAddress := '1-555-555-1212';
CalledParty := 'Frank Borland';
Comment := 'Calling Frank';
tapiRequestMakeCall(pChar(DestAddress),
PChar(Application.Title),
pChar(CalledParty),
PChar(Comment));
end;
end.