How to change the System Volume programmatically

Naredla Nithesh

Hai Every one ...I want to change the System volume .I am using fallowing code......
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace shaped_form
{
class VolumeChange
{
private const int APPCOMMAND_VOLUME_MUTE = 0x80000;
private const int APPCOMMAND_VOLUME_UP = 0xA0000;
private const int APPCOMMAND_VOLUME_DOWN = 0x90000;
private const int WM_APPCOMMAND = 0x319;
[DllImport("user32.dll")]
public static extern IntPtr SendMessageW(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
private void btnMute_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle,(IntPtr)APPCOMMAND_VOLUME_MUTE);
}
private void btnDecVol_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle,(IntPtr)APPCOMMAND_VOLUME_DOWN);
}
private void btnIncVol_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND,this.Handle,(IntPtr)APPCOMMAND_VOLUME_UP);
}
}
}
But I got an error at the highlighted places...as shown below...i got this code from some internet sources

4 Replies

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Naredla Nithesh12y ago
Go and see this link
http://msdn.microsoft.com/en-us/library/aa719104.aspx
Dipankar Biswas12y ago
use C#

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{

private const int APPCOMMAND_VOLUME_MUTE = 0x80000;
private const int APPCOMMAND_VOLUME_UP = 0xA0000;
private const int APPCOMMAND_VOLUME_DOWN = 0x90000;
private const int WM_APPCOMMAND = 0x319;

[DllImport("user32.dll")]
public static extern IntPtr SendMessageW(IntPtr hWnd, int Msg,
IntPtr wParam, IntPtr lParam);
public Form1()
{
InitializeComponent();
}

private void btnMute_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle,
(IntPtr)APPCOMMAND_VOLUME_MUTE);
}

private void button2_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle,
(IntPtr)APPCOMMAND_VOLUME_DOWN);

}

private void button3_Click(object sender, EventArgs e)
{
SendMessageW(this.Handle, WM_APPCOMMAND, this.Handle,
(IntPtr)APPCOMMAND_VOLUME_UP);
}

}
}
Dipankar Biswas12y ago
Imports System
Imports System.Windows.Forms
Imports System.Runtime.InteropServices

Partial Public Class Form2
Inherits Form
Private Const APPCOMMAND_VOLUME_MUTE As Integer = &H80000
Private Const APPCOMMAND_VOLUME_UP As Integer = &HA0000
Private Const APPCOMMAND_VOLUME_DOWN As Integer = &H90000
Private Const WM_APPCOMMAND As Integer = &H319

_
Public Shared Function SendMessageW(ByVal hWnd As IntPtr, _
ByVal Msg As Integer, ByVal wParam As IntPtr, _
ByVal lParam As IntPtr) As IntPtr
End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SendMessageW(Me.Handle, WM_APPCOMMAND, _
Me.Handle, New IntPtr(APPCOMMAND_VOLUME_MUTE))
End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
SendMessageW(Me.Handle, WM_APPCOMMAND, _
Me.Handle, New IntPtr(APPCOMMAND_VOLUME_DOWN))
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
SendMessageW(Me.Handle, WM_APPCOMMAND, _
Me.Handle, New IntPtr(APPCOMMAND_VOLUME_UP))
End Sub
End Class
Vulpes12y ago
It looks like all the code you have in your VolumeChange class is designed to be placed directly within a windows form, not just an ordinary class.

You can tell that from the presence of the 3 button Click handlers for muting, decreasing or increasing the volume.

'this.Handle' will then work because all forms have a Handle property.

So I'd move all the code inside a form and add the 'skeleton' Click handlers for the 3 buttons by double clicking on them within the VS designer, rather than manually.