Unfortunately, you cannnot set the proxy per insnance. Not even per application - it is global. If you chnage it for a .net app, it will impact IE as well.
Here is complete code to change the proxy.
Create a "Form1" with buttons "B_Get" "B_Set" and "B_Disable" and then paste this code.
It should work for you. I used this app as proof of concept for an automatic proxy cycler i built.
Depending on your applications needs, you may be able to switch it, and then switch it back. Note that it WILL impact internet explorer.
To verify that this is working, check internet explorer. You will probably have to open/close the options dialog for IE, but you shouldnt need to restart the browser.
This will also impact .NET apps on the fly - if you run my program while yours is running, you will be able to change the proxy that your program is using.
Imports Microsoft.Win32
Imports System.Runtime.InteropServices
Public Class Form1
<DllImport("wininet.dll")>
Public Shared Function InternetSetOption(hInternet As IntPtr, dwOption As Integer, lpBuffer As IntPtr, dwBufferLength As Integer) As Boolean
End Function
Public Const INTERNET_OPTION_SETTINGS_CHANGED As Integer = 39
Public Const INTERNET_OPTION_REFRESH As Integer = 37
'This function is what is called after editing the registry - this causes internet explorer to update its proxy even if it is already open.
'It also effects the web browser control in any VB.net application that is running.
Public Sub globalProxy_apply()
Dim settingsReturn As Boolean = False
Dim refreshReturn As Boolean = False
settingsReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_SETTINGS_CHANGED, IntPtr.Zero, 0)
If Not settingsReturn Then
MessageBox.Show("Error 001: Line ""InternetSetOption(IntPtr.Zero, INTERNET_OPTION_SETTINGS_CHANGED, IntPtr.Zero, 0)"" failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End If
refreshReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_REFRESH, IntPtr.Zero, 0)
If Not refreshReturn Then
MessageBox.Show("Error 002: Line ""InternetSetOption(IntPtr.Zero, INTERNET_OPTION_REFRESH, IntPtr.Zero, 0)"" failed.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End If
End Sub
Public Function globalProxy_IsProxyEnabled() As Boolean
Try
Dim Regs As RegistryKey = Registry.CurrentUser.CreateSubKey("Software\Microsoft\Windows\CurrentVersion\Internet Settings", RegistryKeyPermissionCheck.ReadWriteSubTree)
If Regs.GetValue("ProxyEnable") <> Nothing Then
If Regs.GetValue("ProxyEnable").ToString() = "0" Then
Return False
Else
Return True
End If
Else
Return False
End If
Catch ex As Exception
MessageBox.Show("Error 01X: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Return False
End Try
End Function
Public Function globalProxy_GetProxyServer() As String
Try
Dim Regs As RegistryKey = Registry.CurrentUser.CreateSubKey("Software\Microsoft\Windows\CurrentVersion\Internet Settings", RegistryKeyPermissionCheck.ReadWriteSubTree)
If Regs.GetValue("ProxyServer") <> Nothing Then
Return Regs.GetValue("ProxyServer").ToString()
Else
Return ""
End If
Catch ex As Exception
MessageBox.Show("Error 02X: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Return ""
End Try
End Function
Public Sub globalProxy_DisableProxy()
Dim regkey As RegistryKey
Try
regkey = Registry.CurrentUser.CreateSubKey("Software\Microsoft\Windows\CurrentVersion\Internet Settings")
regkey.SetValue("ProxyEnable", False, RegistryValueKind.DWord)
regkey.Close()
Catch ex As Exception
MessageBox.Show("Error 03X: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
globalProxy_apply()
End Sub
Public Sub globalProxy_SetProxy(ByVal ServerName As String)
Dim regkey As RegistryKey
Try
regkey = Registry.CurrentUser.CreateSubKey("Software\Microsoft\Windows\CurrentVersion\Internet Settings")
regkey.SetValue("ProxyServer", ServerName, RegistryValueKind.Unknown)
regkey.SetValue("ProxyEnable", True, RegistryValueKind.DWord)
regkey.Close()
Catch ex As Exception
MessageBox.Show("Error 04X: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
globalProxy_apply()
End Sub
Private Sub B_Set_Click(sender As System.Object, e As System.EventArgs) Handles B_Set.Click
If TextBox1.Text = "" Then
globalProxy_DisableProxy()
Else
globalProxy_SetProxy(TextBox1.Text)
End If
End Sub
Private Sub B_Disable_Click(sender As System.Object, e As System.EventArgs) Handles B_Disable.Click
globalProxy_DisableProxy()
End Sub
Private Sub B_Get_Click(sender As System.Object, e As System.EventArgs) Handles B_Get.Click
If globalProxy_IsProxyEnabled() Then
TextBox1.Text = globalProxy_GetProxyServer()
Else
TextBox1.Text = ""
End If
End Sub
End Class