In order to use multiple proxy servers, you need to create the BrowserContext instance for each proxy. This article demonstrates how to implement the WinForms application which loads the specified web page using the different proxies.
In the sample application, the main form contains the address text box, the navigation button, and the tab control. The tab control contains the tab for direct loading (without using the proxy server) and a tab demonstrating the usage of each proxy server from the list of specified proxies.
The configuration of the proxy server is defined using the ProxyConfig class:
C#
public class ProxyConfig
{
public string IpAddress { get; }
public int Port { get; }
public bool IsAuthRequired { get; }
public string Username { get; }
public string Password { get; }
public ProxyConfig(string ipAddress, int port, bool isAuthRequired = false, string username = "", string password = "")
{
IpAddress = ipAddress;
Port = port;
IsAuthRequired = isAuthRequired;
Username = username;
Password = password;
}
public override string ToString()
{
return string.Format("{0}:{1}", IpAddress, Port);
}
}VB.NET
Public Class ProxyConfig
Public ReadOnly Property IpAddress As String
Public ReadOnly Property Port As Integer
Public ReadOnly Property IsAuthRequired As Boolean
Public ReadOnly Property Username As String
Public ReadOnly Property Password As String
Public Sub New(ipAddress As String, port As Integer, Optional isAuthRequired As Boolean = False,
Optional username As String = "", Optional password As String = "")
IpAddress = ipAddress
Port = port
IsAuthRequired = isAuthRequired
Username = username
Password = password
End Sub
Public Overrides Function ToString() As String
Return String.Format("{0}:{1}", IpAddress, Port)
End Function
End ClassIf the proxy requires authentication then such authentication should be performed by the network delegate. The ProxyNetworkDelegate class implements such authentication:
C#
public class ProxyNetworkDelegate : DefaultNetworkDelegate
{
private string user;
private string password;
public ProxyNetworkDelegate(string user, string password)
{
this.user = user;
this.password = password;
}
public override bool OnAuthRequired(AuthRequiredParams parameters)
{
if (parameters.IsProxy)
{
parameters.Username = user;
parameters.Password = password;
}
return false;
}
}VB.NET
Public Class ProxyNetworkDelegate Inherits DefaultNetworkDelegate Private user As String Private password As String Public Sub New(ByVal user As String, ByVal password As String) Me.user = user Me.password = password End Sub Public Overrides Function OnAuthRequired(ByVal parameters As AuthRequiredParams) As Boolean If parameters.IsProxy Then parameters.Username = user parameters.Password = password End If Return False End Function End Class
Each tab page accepts the proxy configuration (the ProxyConfig class instance) and should create the BrowserContext instance according to this configuration. After that, the Browser instance and the BrowserView instance should be created based on the created context:
C#
public class ProxyTabPage : TabPage
{
private ProxyConfig proxyConfig;
private string contextDirectory;
private BrowserContext context;
private Browser browser;
private WinFormsBrowserView browserView;
public ProxyTabPage(ProxyConfig proxyConfig)
{
this.proxyConfig = proxyConfig;
//Generate unique context directory name
contextDirectory = Guid.NewGuid().ToString("N");
Text = proxyConfig != null ? proxyConfig.ToString() : "Direct access";
InitializeBrowser();
}
public void GoToUrl(string url)
{
browser.LoadURL(url);
}
private void InitializeBrowser()
{
BrowserContextParams contextParams = new BrowserContextParams(contextDirectory);
//The BrowserContext should be stored in RAM
contextParams.StorageType = StorageType.MEMORY;
//For non-default proxy settings
if (proxyConfig != null)
{
//Setup the proxy rules
contextParams.ProxyConfig =
new CustomProxyConfig(string.Format("http={0};https={0};socks={0}", proxyConfig.ToString()));
}
context = new BrowserContext(contextParams);
//Check if the proxy server requires authentication
if (proxyConfig != null && proxyConfig.IsAuthRequired)
{
//Create the network delegate and assign it to the context
context.NetworkService.NetworkDelegate =
new ProxyNetworkDelegate(proxyConfig.Username, proxyConfig.Password);
}
browser = BrowserFactory.Create(context);
browserView = new WinFormsBrowserView(browser) {Dock = DockStyle.Fill};
Controls.Add(browserView);
}
public void DisposeBrowser()
{
browserView.Dispose();
browser.Dispose();
context.Dispose();
}
}VB.NET
Public Class ProxyTabPage
Inherits TabPage
Private proxyConfig As ProxyConfig
Private contextDirectory As String
Private context As BrowserContext
Private browser As Browser
Private browserView As WinFormsBrowserView
Public Sub New(ByVal proxyConfig As ProxyConfig)
Me.proxyConfig = proxyConfig
contextDirectory = Guid.NewGuid().ToString("N")
Text = If(proxyConfig IsNot Nothing, proxyConfig.ToString(), "Direct access")
InitializeBrowser()
End Sub
Public Sub GoToUrl(ByVal url As String)
browser.LoadURL(url)
End Sub
Private Sub InitializeBrowser()
Dim contextParams As BrowserContextParams = New BrowserContextParams(contextDirectory)
contextParams.StorageType = StorageType.MEMORY
If proxyConfig IsNot Nothing Then
contextParams.ProxyConfig = New CustomProxyConfig(String.Format("http={0};https={0};socks={0}", proxyConfig.ToString()))
End If
context = New BrowserContext(contextParams)
If proxyConfig IsNot Nothing AndAlso proxyConfig.IsAuthRequired Then
context.NetworkService.NetworkDelegate = New ProxyNetworkDelegate(proxyConfig.Username, proxyConfig.Password)
End If
browser = BrowserFactory.Create(context)
browserView = New WinFormsBrowserView(browser) With {
.Dock = DockStyle.Fill
}
Controls.Add(browserView)
End Sub
Public Sub DisposeBrowser()
browserView.Dispose()
browser.Dispose()
context.Dispose()
End Sub
End ClassThe tab control accepts the list of the proxy server configurations and creates the tab for each proxy and for the direct access:
C#
public class ProxyTabControl : TabControl
{
public List<ProxyConfig> ProxyConfigs { get; }
public ProxyTabControl(List<ProxyConfig> proxyConfigs)
{
ProxyConfigs = proxyConfigs;
CreateProxyTabs();
}
public void GoToUrl(string url)
{
foreach (TabPage tabPage in TabPages)
{
ProxyTabPage proxyTabPage = tabPage as ProxyTabPage;
if (proxyTabPage != null)
{
proxyTabPage.GoToUrl(url);
}
}
}
private void CreateProxyTabs()
{
//Create the tab bor the direct access
ProxyTabPage tabWithoutProxy = new ProxyTabPage(null);
TabPages.Add(tabWithoutProxy);
//Create the tab for the access via proxy
foreach (ProxyConfig proxyConfig in ProxyConfigs)
{
ProxyTabPage tabWithProxy = new ProxyTabPage(proxyConfig);
TabPages.Add(tabWithProxy);
}
}
public void DisposeTabs()
{
foreach (TabPage tabPage in TabPages)
{
ProxyTabPage proxyTabPage = tabPage as ProxyTabPage;
if (proxyTabPage != null)
{
proxyTabPage.DisposeBrowser();
}
}
}
}VB.NET
Public Class ProxyTabControl Inherits TabControl Public ReadOnly Property ProxyConfigs As List(Of ProxyConfig) Public Sub New(ByVal proxyConfigs As List(Of ProxyConfig)) ProxyConfigs = proxyConfigs CreateProxyTabs() End Sub Public Sub GoToUrl(ByVal url As String) For Each tabPage As TabPage In TabPages Dim proxyTabPage As ProxyTabPage = TryCast(tabPage, ProxyTabPage) If proxyTabPage IsNot Nothing Then proxyTabPage.GoToUrl(url) End If Next End Sub Private Sub CreateProxyTabs() Dim tabWithoutProxy As ProxyTabPage = New ProxyTabPage(Nothing) TabPages.Add(tabWithoutProxy) For Each proxyConfig As ProxyConfig In ProxyConfigs Dim tabWithProxy As ProxyTabPage = New ProxyTabPage(proxyConfig) TabPages.Add(tabWithProxy) Next End Sub Public Sub DisposeTabs() For Each tabPage As TabPage In TabPages Dim proxyTabPage As ProxyTabPage = TryCast(tabPage, ProxyTabPage) If proxyTabPage IsNot Nothing Then proxyTabPage.DisposeBrowser() End If Next End Sub End Class
In the MainForm constructor the ProxyTabControl is created using the defined proxy list:
C#
public partial class MainForm : Form
{
private ProxyTabControl tabControl;
public MainForm()
{
InitializeComponent();
tabControl = new ProxyTabControl(new List<ProxyConfig>()
{
new ProxyConfig("23.111.166.114", 8080),
new ProxyConfig("52.224.181.154", 3128)
})
{ Dock = DockStyle.Fill };
BrowserTabPanel.Controls.Add(tabControl);
AddressTextBox.Text = "whatismyproxy.com";
tabControl.GoToUrl(AddressTextBox.Text);
Closed += MainForm_Closed;
}
private void MainForm_Closed(object sender, EventArgs e)
{
tabControl.DisposeTabs();
}
private void GoButton_Click(object sender, EventArgs e)
{
tabControl.GoToUrl(AddressTextBox.Text);
}
}VB.NET
Public Partial Class MainForm
Inherits Form
Private tabControl As ProxyTabControl
Public Sub New()
InitializeComponent()
tabControl = New ProxyTabControl(New List(Of ProxyConfig)() From {
New ProxyConfig("23.111.166.114", 8080),
New ProxyConfig("52.224.181.154", 3128)
}) With {
.Dock = DockStyle.Fill
}
BrowserTabPanel.Controls.Add(tabControl)
AddressTextBox.Text = "whatismyproxy.com"
tabControl.GoToUrl(AddressTextBox.Text)
Closed += AddressOf MainForm_Closed
End Sub
Private Sub MainForm_Closed(ByVal sender As Object, ByVal e As EventArgs)
tabControl.DisposeTabs()
End Sub
Private Sub GoButton_Click(ByVal sender As Object, ByVal e As EventArgs)
tabControl.GoToUrl(AddressTextBox.Text)
End Sub
End Class