i find the problem,but i don't clear about it.

i see a article named 'Tapi 3.0 Application development using C#.NET By devang_bison' in the http://www.codeproject.com

the link : demo and source

look at this code script:

bcc = ln.CreateCall(textBox1.Text,TapiConstants.LINEADDRESSTYPE_PHONENUMBER | TapiConstants.LINEADDRESSTYPE_IPADDRESS,TapiConstants.TAPIMEDIATYPE_AUDIO);

CreateCall is no problem,but bcc.Connect throw out an expection.I change to

bcc = ln.CreateCall(textBox1.Text,TapiConstants.LINEADDRESSTYPE_PHONENUMBER ,TapiConstants.TAPIMEDIATYPE_AUDIO);

the program can run.I think it's maybe the computer not support the TapiConstants .In my opinion,it's best to use one TapiConstants.

Latestly,I study how to play the music to the recieve when using the computer telephone.I hope get help,thanks!

Thank for this solution, I can run the application.

I have a voice modem , the model is Motorola SM56 Voice Modem. It is a Unimodem Half-Duplex Audio Device.

I have speaker and mic. 100% sure it is work.

Now the problem I face is I can make call, I can hear the dial tone from my speaker. The other party cannot hear what I say, I only can hear people talking. What is the problem

In another case,
I try using "dialer.exe" windows application, by using this application. Other party can hear what I say, but I cannot hear them.

Anyone can help me

i have same problem.i changed the code but i recieved this exception : Uninitialized object (Exception from HRESULT: 0x80040007 (OLE_E_BLANK))

what should i do !