getting digitized data from sound card by c#

Thanks
i've found a code that records voice from Microphone:

1. Open C#.net web applications. And added the blow namespace.

using Microsoft.VisualBasic.Devices;
using Microsoft.VisualBasic;
using System.Runtime.InteropServices;

2. Add the below API.
[DllImport("winmm.dll", EntryPoint = "mciSendStringA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
private static extern int mciSendString(string lpstrCommand, string lpstrReturnString, int uReturnLength, int hwndCallback);

3. Create three Buttons and given the below name and text for the buttons.

1. Record
2. SaveStop
3. Read

1. Under Record Button Click paste the below Code:

// record from microphone
mciSendString("open new Type waveaudio Alias recsound", "", 0, 0);
mciSendString("record recsound", "", 0, 0);

2. Under Save / Stop button Click,


// stop and save
mciSendString("save recsound c:\record.wav", "", 0, 0);
mciSendString("close recsound ", "", 0, 0);
Computer c = new Computer();
c.Audio.Stop();

3. Under Read Button Click

Computer computer = new Computer();
computer.Audio.Play("c:\record.wav", AudioPlayMode.Background);


Save and Execute it.

but i dont know how to add sound card's APIs & usings to my project
when i add lines directly to code , there are some errors i think i should add them in some where elese too

i'd be so glad if you help me