using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using System.Runtime.InteropServices; namespace VolumeControl { public partial class Form1 : Form { [DllImport("winmm.dll")] public static extern int waveOutGetVolume(IntPtr hwo, out uint dwVolume); [DllImport("winmm.dll")] public static extern int waveOutSetVolume(IntPtr hwo, uint dwVolume); public Form1() { InitializeComponent(); // By the default set the volume to 0 uint CurrVol = 0; // At this point, CurrVol gets assigned the volume waveOutGetVolume(IntPtr.Zero, out CurrVol); // Calculate the volume ushort CalcVol = (ushort)(CurrVol & 0x0000ffff); // Get the volume on a scale of 1 to 10 (to fit the trackbar) trackWave.Value = CalcVol / (ushort.MaxValue / 10); } private void trackWave_Scroll(object sender, EventArgs e) { // Calculate the volume that's being set int NewVolume = ((ushort.MaxValue / 10) * trackWave.Value); // Set the same volume for both the left and the right channels uint NewVolumeAllChannels = (((uint)NewVolume & 0x0000ffff) | ((uint)NewVolume << 16)); // Set the volume waveOutSetVolume(IntPtr.Zero, NewVolumeAllChannels); } } }