How to record sound from a microphone?

Question

Audio

Unable to implement microphone recording with NAudio. The file is simply not being created, what is the reason?

using NAudio.Wave;
 
namespace Recorder
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        WaveIn waveIn;
        WaveFileWriter writer;
        string outputFilename = "D:/demo.wav";
 
        void waveIn_DataAvailable(object sender, WaveInEventArgs e)
        {
            writer.Write(e.Buffer, 0, e.BytesRecorded);
        }
 
        void waveIn_RecordingStopped(object sender, EventArgs e)
        {
            waveIn.Dispose();
            waveIn = null;
            writer.Close();
            writer = null;
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            waveIn = new WaveIn();
            waveIn.DeviceNumber = 0;
            waveIn.DataAvailable += waveIn_DataAvailable;
            waveIn.RecordingStopped += new EventHandler<NAudio.Wave.StoppedEventArgs>(waveIn_RecordingStopped);
            waveIn.WaveFormat = new WaveFormat(44100, 2);
            writer = new WaveFileWriter(outputFilename, waveIn.WaveFormat);
            waveIn.StartRecording();
        }
 
        private void button2_Click(object sender, EventArgs e)
        {
            waveIn.StopRecording();
        }
 
 
    }
}

Answer 1

using NAudio.Wave;

namespace Record
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        WaveIn waveIn;
        WaveFileWriter waveWriter;


        private void waveIn_DataAvailable(object sender, WaveInEventArgs e)
        {
            if (waveWriter == null) return;

            waveWriter.Write(e.Buffer, 0, e.BytesRecorded);
            waveWriter.Flush();
        }


        private void button1_Click(object sender, EventArgs e)
        {
            waveIn = new WaveIn();
            waveIn.DeviceNumber = 0;
            string outputFilename = @"D:/demo.wav";
            waveIn.WaveFormat = new WaveFormat(44100, WaveIn.GetCapabilities(waveIn.DeviceNumber).Channels);

            waveIn.DataAvailable += new EventHandler<WaveInEventArgs>(waveIn_DataAvailable);
            waveWriter = new WaveFileWriter(outputFilename, waveIn.WaveFormat);
            waveIn.StartRecording();
        }

        private void button2_Click(object sender, EventArgs e)
        {

            if (waveIn != null)
            {
                waveIn.StopRecording();
                waveIn.Dispose();
                waveIn = null;
            }
            if (waveWriter != null)
            {
                waveWriter.Dispose();
                waveWriter = null;
            }
        }
    }
}