By default there is no validation control in ASP.NET to work with the checkbox control. However, in certain cases you may want to use validation on a checkbox such as one that would require them to accept the terms and services of a web site or registration process. To do this:
Right click the project in your solution explorer.
Select add new item…
Select a web form.
Name it ‘Default.aspx’.
Click add.
Open Default.aspx up to design mode.
Drag and drop a checkbox onto the web form.
Drag and drop a customvalidator next to the checkbox.
Change the ErrorMessage property to ‘You must check the box’.
Change the ForeColor property to ‘Red’.
Check the Text property to ‘*’.
Add a line break after the customvalidator.
Drag and drop a button under the checkbox.
Add a line break after the button.
Drag and drop a validationsummary under the button.

Validating the CheckboxNext, we want to add in some simple code on the ServerValidate event of the customvalidator that we added. To do this:
Double click the customvalidator to generate the ServerValidate event method.
Add in the following code to the CustomValidator_ServerValidate event method:

Create class FileProtectHandler.cs in the project and add methods as follows:

using System;

using System.Web;

using System.Web.Security;

using System.IO;

namespace Custom.Handlers

{

/// <summary>

/// Handles processing requests for protected web application files, such as reports/*.pdf

/// The reports are checked by the user role to determine access.

/// </summary>

public class FileProtectionHandler : IHttpHandler, System.Web.SessionState.IRequiresSessionState

{

#region IHttpHandler Members

public bool IsReusable

{

get

{

return false;

}

public void ProcessRequest(HttpContext context)

{

switch (context.Request.HttpMethod)

{

case "GET":

{

// Is the user logged-in?

//if (!context.User.Identity.IsAuthenticated)

//{

// FormsAuthentication.RedirectToLoginPage();

// return;

//}

string requestedFile = context.Server.MapPath(context.Request.FilePath);

// Verify the user has access to the User role.

if (Convert.ToString(context.Session["Username"]) == "demo")

{

SendContentTypeAndFile(context, requestedFile);

}

else

{

context.Response.Redirect("~/adm/login05.aspx");

}

break;

}

#endregion

private HttpContext SendContentTypeAndFile(HttpContext context, String strFile)

{

context.Response.ContentType = GetContentType(strFile);

context.Response.TransmitFile(strFile);

context.Response.End();

return context;

}

private string GetContentType(string filename)

{

// used to set the encoding for the reponse stream

string res = null;

FileInfo fileinfo = new FileInfo(filename);

if (fileinfo.Exists)

{

switch (fileinfo.Extension.Remove(0, 1).ToLower())

{

case "pdf":

res = "application/pdf";

break;

case "doc":

case "docx":

res = "application/msword";

break;

case "xls":

case "xlsx":

res = "application/vnd.ms-excel";

break;

case "rtf":

res = "application/x-rtf";

break;

case "txt":

res = "text/plain";

break;

case "jpeg":

case "jpg":

res = "image/jpg";

break;

case "bmp":

res = "image/bmp";

break;

case "png":

res = "image/png";

break;

case "gif":

res = "image/gif";

break;

default:

res = "application/octet-stream";

break;

}

return res;

}

return null;

}

Add the tags in the Web.config File according to the handler namespace

</handlers>

</httpHandlers>

AspDotNetFreaks - An answer to your Queries

Tuesday, August 28, 2012

Validate a CheckBox with a CustomValidator in ASP.NET 4.0 and C#

Restrict Files Access From Unauthorized access using File Handlers

Create class FileProtectHandler.cs in the project and add methods as follows:

Add the tags in the Web.config File according to the handler namespace