an item with same key already exists

I have a simple mvc website now i want to create a user registration process when i click the register button after putting all the values for user like name,email,address,phone then my code is not going to the controller to debug instead it gives the error"An item with the same key has already been added."
below is my model i have checked that no two properties have the same name .

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
using System.Data.SqlClient;
using System.Web.Mvc;
using System.Drawing;
using System.Drawing.Imaging;

namespace BusinessApplicationTemplate.Models
{

public class Login
{
[Required(ErrorMessage = "Email Id Required")]
[DisplayName("Email ID")]
[RegularExpression(@"^\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$",
ErrorMessage = "Email Format is wrong")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string EmailId
{
get;
set;
}

[DataType(DataType.Password)]
[Required(ErrorMessage = "Password Required")]
[DisplayName("Password")]
[StringLength(30, ErrorMessage = ":Less than 30 characters")]
public string Password
{
get;
set;
}
//[Display(Name = "Remember me?")]
//public bool RememberMe { get; set; }
public bool IsUserExist(string emailid, string password)
{
bool flag = false;
SqlConnection connection = new SqlConnection(
System.Configuration.ConfigurationManager.ConnectionStrings["cs"].ConnectionString);
connection.Open();
SqlCommand command = new SqlCommand("select count(*) from Users where userID='" + emailid + "' and Password='" + password + "'", connection);
flag = Convert.ToBoolean(command.ExecuteScalar());
connection.Close();
return flag;
}

public class CaptchImageAction : ActionResult
{
public Color BackgroundColor { get; set; }
public Color RandomTextColor { get; set; }
public string RandomText { get; set; }
public override void ExecuteResult(ControllerContext context)
{
RenderCaptchaImage(context);
}
private void RenderCaptchaImage(ControllerContext context)
{
Bitmap objBmp = new Bitmap(150, 60);
Graphics objGraphic = Graphics.FromImage(objBmp);
objGraphic.Clear(BackgroundColor);
SolidBrush objBrush = new SolidBrush(RandomTextColor);
Font objFont = null;
int a;
string myFont, str;
string[] crypticsFont = new string[11];
crypticsFont[0] = "Times New roman";
crypticsFont[1] = "Verdana";
crypticsFont[2] = "Sylfaen";
crypticsFont[3] = "Microsoft Sans Serif";
crypticsFont[4] = "Algerian";
crypticsFont[5] = "Agency FB";
crypticsFont[6] = "Andalus";
crypticsFont[7] = "Cambria";
crypticsFont[8] = "Calibri";
crypticsFont[9] = "Courier";
crypticsFont[10] = "Tahoma";
for (a = 0; a < RandomText.Length; a++)
{
myFont = crypticsFont[a];
objFont = new Font(myFont, 18, FontStyle.Bold | FontStyle.Italic |
FontStyle.Strikeout);
str = RandomText.Substring(a, 1);
objGraphic.DrawString(str, objFont, objBrush, a * 20, 20);
objGraphic.Flush();
}
context.HttpContext.Response.ContentType = "image/GF";
objBmp.Save(context.HttpContext.Response.OutputStream, ImageFormat.Gif);
objFont.Dispose();
objGraphic.Dispose();
objBmp.Dispose();
}
}
}

public class Register
{
[Required(ErrorMessage = "FirstName Required:")]
[DisplayName("First Name:")]
[RegularExpression(@"^[a-zA-Z'.\s]{1,40}$", ErrorMessage = "Special Characters not allowed")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string FirstName { get; set; }

[Required(ErrorMessage = "LastName Required:")]
[RegularExpression(@"^[a-zA-Z'.\s]{1,40}$", ErrorMessage = "Special Characters not allowed")]
[DisplayName("Last Name:")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string LastName { get; set; }

[Required(ErrorMessage = "EmailId Required:")]
[DisplayName("Email Id:")]
[RegularExpression(@"^\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$",
ErrorMessage = "Email Format is wrong")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string EmailIds { get; set; }

[Required(ErrorMessage = "Password Required:")]
[DataType(DataType.Password)]
[DisplayName("Password:")]
[StringLength(30, ErrorMessage = "Less than 30 characters")]
public string psword { get; set; }

[Required(ErrorMessage = "Confirm Password Required:")]
[DataType(DataType.Password)]
[Compare("Password", ErrorMessage = "Confirm not matched.")]
[Display(Name = "password:")]
[StringLength(30, ErrorMessage = "Less than 30 characters")]
public string ConfirmPassword { get; set; }

[Required(ErrorMessage = "Street Address Required")]
[DisplayName("Street Address1:")]
[StringLength(100, ErrorMessage = "Less than 100 characters")]
public string StreetAdd1 { get; set; }

[DisplayName("Street Address2:")]
[StringLength(100, ErrorMessage = "Less than 100 characters")]
public string StreetAdd2 { get; set; }

[Required(ErrorMessage = "City Required")]
[DisplayName("City:")]
[RegularExpression(@"^[a-zA-Z'.\s]{1,40}$", ErrorMessage = "Special Characters not allowed")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string City { get; set; }

[Required(ErrorMessage = "State Required")]
[DisplayName("State:")]
[RegularExpression(@"^[a-zA-Z'.\s]{1,40}$", ErrorMessage = "Special Characters not allowed")]
[StringLength(50, ErrorMessage = "Less than 50 characters")]
public string State { get; set; }

[Required(ErrorMessage = "ZipCode Required")]
[DisplayName("Zip Code:")]
[StringLength(20, ErrorMessage = "Less than 20 characters")]
public string Zip { get; set; }

[Required(ErrorMessage = "Enter Verification Code")]
[DisplayName("Verification Code:")]
public string Captcha { get; set; }
public string Remembermes { get; set; }
public bool IsUserExist(string emailid)
{
bool flag = false;
SqlConnection connection = new SqlConnection
(System.Configuration.ConfigurationManager.ConnectionStrings["cs"].ConnectionString);
connection.Open();
SqlCommand command = new SqlCommand("select count(*) from Users where userID='" + emailid + "'", connection);
flag = Convert.ToBoolean(command.ExecuteScalar());
connection.Close();
return flag;
}

public bool Insert()
{
bool flag = false;
if (!IsUserExist(EmailIds))
{
SqlConnection connection = new SqlConnection
(System.Configuration.ConfigurationManager.ConnectionStrings["cs"].ConnectionString);
connection.Open();
SqlCommand command = new SqlCommand("insert into Users values('" + FirstName + "','" + LastName + "','" + EmailIds + "','" + psword + "', '" + StreetAdd1 + "','" + StreetAdd2 + "','" + City + "','" + State + "', '" + Zip + "')", connection);
flag = Convert.ToBoolean(command.ExecuteNonQuery());
connection.Close();
return flag;
}
return flag;
}
}
}

What I have tried:

Basically i have two classes in one class check the above code i have inspact it and icould not found any same name for properties

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Rajeev Punhani10y ago
Hi Mark,
There is an issue in viewModelVm.cs .Here you are having code like.
publicListslider{get;set;}
publicListService{get;set;}
publicServiceservice{get;set;}
publicLoginlogin{get;set;}
publicRegisterregister{get;set;}
The issue in above snippet in in Line 2 and 3.Just change the variable names and it works.
publicListslider{get;set;}
publicListservice{get;set;}
publicServiceservice1{get;set;}
publicLoginlogin{get;set;}
publicRegisterregister{get;set;}
If the above solution is helpful then,accept the answer.
Rajeev Punhani10y ago
Hi Mark,
I think you are trying to implement the code from this link.
https://www.mindstick.com/Articles/776/login-and-registration-form-in-asp-dot-net-mvc
The above mentioned error comes when you have two properties with same name.
Please share the zip code so that we can help you out.
Bikesh Srivastava10y ago
i have written article on this.see..
http://www.c-sharpcorner.com/article/remote-validation-in-mvc-5-to-check-if-username-and-email-id-exists/
Mark Tabor10y ago
The above mentioned issue is not from the inline query as when i press the Register button i could not get into the controller so that i can debug before going into the code my application gives the error as an item with same key has already been added
Nitin Sontakke10y ago
Not answering your question, but looking at your code, i would like to suggest that you start using stored procedures for even single line queries. This is because, code like this is prone to sql injection attacks. For example when trying to login try putting following invalid password as it is (including single quotation marks!) and see what happens:
' or 1=1--'