© 2025 Pashant Khandelwal
© 2025 Pashant Khandelwal
Using CAPTCHA was never easy for me before I got a class from an unknown user on a community forum post. I have just re-used the class to get my work done. The class is extremely easy to use and let you incorporate the CAPTCHA into your application in just few lines of code.
You can set the height and width of the CAPTCHA image while initializing the CAPTCHA class. The CAPTCHA image generated from the class can be set to the image control directly or it can be save to the local path and then set to the image control. For this example I am saving it to the local path and then set to the image control. And the CAPTCHA image code generated by the class is automatically set to the session variable named CaptchaCode.
Time to get some hand on it
On the page get an image control to display CAPTCHA image, a textbox where user will enter the CAPTCHA text and a button when clicked, we can check and validate if the code entered is correct or not. Plug the DLL in your ASP.NET project and go to the Page_Load event. Here we will generate the image of the height and width we wish to have for out CAPTCHA image and then save the image to the CaptchaImages folder with the random image code generated. The code on the Page_Load event goes like this:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
CaptchaImage cImage = new CaptchaImage(CaptchaImage.generateRandomCode(), 140, 40);
cImage.Image.Save(Server.MapPath("~\\CaptchaImages\\" + Convert.ToString(Session["CaptchaCode"]) + ".jpg"), ImageFormat.Jpeg);
CaptachaImage.ImageUrl = "~\\CaptchaImages\\" + Convert.ToString(Session["CaptchaCode"]) + ".jpg";
cImage.Dispose();
}
CaptchaCode = Convert.ToString(Session["CaptchaCode"]);
}
Before you can use the above code, declare a public variable which I have used to hold the value of the CAPTCHA code. I named it CaptchaCode. You can name it whatever you like it. We will be using this variable later to check it against the user input. Hit F5 to start and test your application. If everything is in place and you will be able to see the below output.
To check if the user enters the correct CAPTCHA code, we must have an event on button click which will validate the user input and prompt the user if CAPTCHA code is correct or incorrect. The code on the button click is:
protected void btn_Validate(object sender, EventArgs e)
{
if (CaptchaCode == txt_ccode.Text)
{
ClientScript.RegisterClientScriptBlock(typeof(Page), "ValidateMsg", "<script>alert('You entered Correct CAPTCHA Code!');</script>");
}
else
{
ClientScript.RegisterClientScriptBlock(typeof(Page), "ValidateMsg", "<script>alert('You entered INCORRECT CAPTCHA Code!');</script>");
}
}
The above code will check the CAPTCHA code entered by the user and check against the CAPTCHA code we previously saved in the session variable (CaptchaCode). If the validation is a success, user will get the message notifying him that he enters correct CAPTCHA code or the error message otherwise.
And that’s it, we have successfully implement a CAPTCHA in our ASP.NET application. So, here are few things we can do with this CAPTCHA library:
I have build the sample project in ASP.NET 4.0, if you wanted to use the library in ASP.NET 3.x, then compile the project with lower version of ASP.NET and it will work perfectly. The below zip file contains both the projects.
Download: Captcha.NET.zip (377.63 kb)
Building auto-complete feature with jQuery is easy and you can build this in no time. It’s your wish if you want to use ADO.NET or EF (LINQ) to get this done, it works great for all. The sample application I build is using both ADO.NET and EF. So let’s begin up getting files under one hood.
Use the below live links for jQuery auto-complete and CSS.
<link rel="stylesheet" href="http://dev.jquery.com/view/trunk/plugins/autocomplete/jquery.autocomplete.css" type="text/css" /> <script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/autocomplete/jquery.autocomplete.js"></script>
You can also download these files and use them in your project, if you are planning to run your application offline. For this demonstration, I have downloaded the files. I am using both ADO.NET and LINQ to auto-complete with jQuery auto-complete pug-in.
Starting up with ADO.NET, as we were/are using this for so many years now and therefore there should be no problem for anyone using it. Simple page behind code to get the full list of countries in the world (I hope I have all of them) and seperate each country name with a ‘|’ pipe symbol so I can split countries name and set it to the text box for auto-complete.
public partial class _Default : System.Web.UI.Page
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString);
SqlCommand cmd;
SqlDataReader dr;
public string Listcountries;
private string countryName()
{
StringBuilder sb = new StringBuilder();
cmd = new SqlCommand("Select country_name from Country order by country_name", con);
con.Open();
dr = cmd.ExecuteReader();
while (dr.Read())
{
sb.Append(Convert.ToString(dr[0] + "|"));
}
return Convert.ToString(sb);
}
protected void Page_Load(object sender, EventArgs e)
{
Listcountries = countryName();
}
}
Done with code behind and now only requires few lines of client script on the page to get the auto-complete running.
<script type="text/javascript">
$(document).ready(function () {
var cc = '<%=Listcountries%>'.split("|");
$("#autoText").autocomplete(cc);
});
</script>
The same can be done with LINQ but the jQuery script part will be the same.
public partial class AutocompleteLINQ : System.Web.UI.Page
{
DeveloperDBEntities db = new DeveloperDBEntities();
public IQueryable countries;
public string Listcountries;
protected void Page_Load(object sender, EventArgs e)
{
countries = from c in db.Countries select c;
foreach (Country cobj in countries)
{
Listcountries += cobj.Country_Name + "|";
}
}
}
Just for your ease to use this project as it is, I have included the SQL scripts for the country table. Hope this helps you in building another great or a part of your application.
Download: JqueryAutoComplete.zip (210.73 kb)
Recently, someone on MSDN forums asked this question on how to disable the “X” a.k.a. close button in his windows form application so the user is forced to close the application from the cancel button on the form and not from the close button. He wanted this for his application which requires registration first before a user can start using his application.
I don’t know the answer so I bing arond a bit and find a solution posted by someone though I don’t have the name but it worked like a charm….!!
We need some interoperability to do this, therefore get the namespace System.Runtime.InteropServices Code:
private const int MF_BYPOSITION = 0x400;
[DllImport("User32")]
private static extern int RemoveMenu(IntPtr hMenu, int nPosition, int wFlags);
[DllImport("User32")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
[DllImport("User32")]
private static extern int GetMenuItemCount(IntPtr hWnd);
Below code goes to the load event of your form:
IntPtr hMenu = GetSystemMenu(this.Handle, false); int menuItemCount = GetMenuItemCount(hMenu); RemoveMenu(hMenu, menuItemCount - 1, MF_BYPOSITION);
Time to press ‘F5’….and the close button is now disabled on the form.
Download: CloseButton.zip (43.08 kb)
Crystal reports is one of the most widely used reporting component in Visual Studio. But this time it goes missing from the final release of Visual Studio 2010. Crystal Reports for Visual Studio 2010 is now available for download to all the Visual Studio 2010 users and is for free of cost as always.
Download Links:
Download Crystal Reports for Visual Studio 2010
Getting Started with Crystal Reports for Visual Studio 2010
Tutorials for Crystal Reports for Visual Studio 2010
Related Areas
I was just surfing the net in search for some fundoo tutorial on WPF and by chance (I don’t meant to visit that site), I get this class which I feel is pretty helpful. A simple wrapper class to conver time. the class allows you to convert:
This can be pretty usefull. The class is as follows:
using System;
public static class TimeSpanUtil
{
#region To days
public static double ConvertMillisecondsToDays(double milliseconds)
{
return TimeSpan.FromMilliseconds(milliseconds).TotalDays;
}
public static double ConvertSecondsToDays(double seconds)
{
return TimeSpan.FromSeconds(seconds).TotalDays;
}
public static double ConvertMinutesToDays(double minutes)
{
return TimeSpan.FromMinutes(minutes).TotalDays;
}
public static double ConvertHoursToDays(double hours)
{
return TimeSpan.FromHours(hours).TotalDays;
}
#endregion
#region To hours
public static double ConvertMillisecondsToHours(double milliseconds)
{
return TimeSpan.FromMilliseconds(milliseconds).TotalHours;
}
public static double ConvertSecondsToHours(double seconds)
{
return TimeSpan.FromSeconds(seconds).TotalHours;
}
public static double ConvertMinutesToHours(double minutes)
{
return TimeSpan.FromMinutes(minutes).TotalHours;
}
public static double ConvertDaysToHours(double days)
{
return TimeSpan.FromHours(days).TotalHours;
}
#endregion
#region To minutes
public static double ConvertMillisecondsToMinutes(double milliseconds)
{
return TimeSpan.FromMilliseconds(milliseconds).TotalMinutes;
}
public static double ConvertSecondsToMinutes(double seconds)
{
return TimeSpan.FromSeconds(seconds).TotalMinutes;
}
public static double ConvertHoursToMinutes(double hours)
{
return TimeSpan.FromHours(hours).TotalMinutes;
}
public static double ConvertDaysToMinutes(double days)
{
return TimeSpan.FromDays(days).TotalMinutes;
}
#endregion
#region To seconds
public static double ConvertMillisecondsToSeconds(double milliseconds)
{
return TimeSpan.FromMilliseconds(milliseconds).TotalSeconds;
}
public static double ConvertMinutesToSeconds(double minutes)
{
return TimeSpan.FromMinutes(minutes).TotalSeconds;
}
public static double ConvertHoursToSeconds(double hours)
{
return TimeSpan.FromHours(hours).TotalSeconds;
}
public static double ConvertDaysToSeconds(double days)
{
return TimeSpan.FromDays(days).TotalSeconds;
}
#endregion
#region To milliseconds
public static double ConvertSecondsToMilliseconds(double seconds)
{
return TimeSpan.FromSeconds(seconds).TotalMilliseconds;
}
public static double ConvertMinutesToMilliseconds(double minutes)
{
return TimeSpan.FromMinutes(minutes).TotalMilliseconds;
}
public static double ConvertHoursToMilliseconds(double hours)
{
return TimeSpan.FromHours(hours).TotalMilliseconds;
}
public static double ConvertDaysToMilliseconds(double days)
{
return TimeSpan.FromDays(days).TotalMilliseconds;
}
#endregion
}