Stack Trace from the exception

at System.Web.StaticFileHandler.GetFileInfo(String virtualPathWithPathInfo, String physicalPath, HttpResponse response)
at System.Web.StaticFileHandler.ProcessRequestInternal(HttpContext context)
at System.Web.DefaultHttpHandler.BeginProcessRequest(HttpContext context, AsyncCallback callback, Object state)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

After doing some search we got an option where we can find the file causing the exception. We created a string variable and put a break point over there and debugged the code. It will display the filename causing the exception. In our case it was a HTML file which was used in a Javascript to set an IFRAME source, unfortunately the developer who copied the script missed the HTML and it was causing the exception.

Here is the code.

void Application_Error(object sender, EventArgs e)
{
Exception err = Server.GetLastError();
//Insert a break point and run in debug mode.
string fileName = Context.Request.FilePath;
 Application["UnhandledException"] = err;
}

 var controls = from control in this.Controls
                           select control;

But this will generate a compile time error – Could not find an implementation of the query pattern for source type ‘System.Windows.Forms.Control.ControlCollection’. ‘Select’ not found. Consider explicitly specifying the type of the range variable ‘control’. But the error was self explanatory, I need to specify the type of the control. And here is the modified version.

var controls = from Control control in this.Controls
                           select control;

And if you want to select specific type of controls you need to apply a where condition.

var textboxes = from Control textbox in this.Controls
                where textbox is TextBox
                select textbox;

There is some other inbuilt operators is also available to select specific controls, like OfType()

var textboxes = from textbox in this.Controls.OfType<TextBox>()
                select textbox;

In this method we don’t need to specify the type of the control in the from statement. And one of interesting LINQ extension method is the Cast<> method, which helps to enable the standard query operators to be invoked on non-generic collections by supplying the necessary type information. You can get more information from here.

this.ddlItems.SelectedIndex = -1;
foreach (ListItem item in this.ddlItems.Items)
{
    if (item.Text.Equals("Item", StringComparison.CurrentCultureIgnoreCase))
    {
        item.Selected = true;
        break;
    }
}

It is a nice option, I rewrote it as an extension method and works fine. Later I thought of wrting more generic FindByTextMethod() and here the extension method.

/// <summary>
/// Searches the Collection of ListItem with a ListItem.Text property contains the specified text
/// </summary>
/// <param name="items"></param>
/// <param name="text">The text to search for.</param>
/// <param name="stringComparison">One of the System.StringComparison values.</param>
/// <returns>ListItem if the collection contains the text, null otherwise.</returns>
public static ListItem FindByText(this ListItemCollection items,
    string text,
    StringComparison comparisonType)
{
    ListItem result = items.OfType<ListItem>().
        FirstOrDefault(_string => _string.Text.Equals(text, comparisonType));
    return result;
}

And you can use it like this

this.ddlItems.Items.FindByText("Item", StringComparison.CurrentCultureIgnoreCase).Selected = true;

Happy Coding

We need to modify the web.config, like the implementation of Forms Authentication in ASP.Net.

Create / Add a connection string to active directory database.

<connectionStrings>
<add name="ADConnectionString" connectionString="LDAP://DOMAIN.SUBDOMAIN/DC=DOMAIN,DC= SUBDOMAIN "/>
</connectionStrings>

Configure Membership node in the web.config with ActiveDirectoryMembershipProvider.

<membership defaultProvider="MembershipADProvider">
  <providers>
    <add name="MembershipADProvider"
         type="System.Web.Security.ActiveDirectoryMembershipProvider, System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
         applicationName="dotnetthoughts"
         connectionStringName=" ADConnectionString "
         attributeMapUsername="sAMAccountName"/>
  </providers>
</membership>

You can also provide the Username / Password in this using connectionUsername , connectionPassword attributes.

Modify the Authentication mode and Authorization nodes for controlling the access permissions. Currently I am using Forms Authentication defaults. (default.aspx – Home Page, and Login.aspx – Login Page)

<authentication mode="Forms" />
<authorization>
    <deny users="?" />
    <allow users="*" />
</authorization>

Almost done. Now drag and drop Login control from Toolbox > Login tab to Login.aspx. Run the application, say OK to the Debug mode confirmation from Visual Studio. As we are configured the Authentication provider we don’t need to write any Code to Authentication.

If you don’t want to use login control, you can do something like this in the code behind for the authentication.

if (Membership.ValidateUser(this.txtUsername.Text, this.txtPassword.Text))
{
    FormsAuthentication.RedirectFromLoginPage(this.txtUsername.Text, false);
}
else
{
    Response.Write("Authentication failed.\nUsername / Password Invalid");
}

Thanks to Sreenaja for the initial implementation. Happy Coding

<form id="form1" runat="server" defaultbutton="cmdSubmit">
<asp:Panel runat="server" ID="plMain" DefaultButton="cmdSubmit">

Form tag also supports “defaultfocus” this property allows to focus to control, on Page Load.

<form id="form1" runat="server" defaultbutton="cmdSubmit" defaultfocus="txtUser">

If you are using Master Pages, there will be some slight difference because, the Form tag will not be available in the content Pages. It can fix using code behind, using FindControl method.

(Page.Master.FindControl("Form1") as HtmlForm).DefaultButton = this.cmdSubmit.UniqueID;

Also you can do something like this

Page.Master.Page.Form.DefaultButton = cmdSubmit.UniqueID;

Happy Coding

function ValidateRadioButtons(source, arguments) {
    var radio1 = document.getElementById(source.Radio1);
    var radio2 = document.getElementById(source.Radio2);
    var radio4 = document.getElementById(source.Radio4);
    var radio3 = document.getElementById(source.Radio3);
    var result = radio1.checked || radio2.checked || radio3.checked || radio4.checked;
    arguments.IsValid = result;
}

This is the JavaScript function which implements the validation logic. You can get the controls as part of the Source object. To get the Source.Radio1, you need to register the Radio1 as ClientValidator attribute. You can do some C# code like this.

protected void Page_Load(object sender, EventArgs e)
{
    this.Page.ClientScript.RegisterExpandoAttribute(customCheck.ClientID, "Radio1", this.radio1.ClientID, false);
    this.Page.ClientScript.RegisterExpandoAttribute(customCheck.ClientID, "Radio2", this.radio2.ClientID, false);
    this.Page.ClientScript.RegisterExpandoAttribute(customCheck.ClientID, "Radio3", this.radio3.ClientID, false);
    this.Page.ClientScript.RegisterExpandoAttribute(customCheck.ClientID, "Radio4", this.radio4.ClientID, false);
}

And the ASPX Code is like this

<asp:CustomValidator runat="server" ID="customCheck" ClientValidationFunction="ValidateRadioButtons"
        ErrorMessage="Choose any option" />

And here is the Output code generated for the custom validator.

Custom validator output rendering

Happy Coding.