Validate multiple valid emails separated by semicolon

Validate multiple valid emails separated by semicolon
There are various ways to validate them
1. Using custom validator and calling the javascript

 <asp:CustomValidator ID="custValEmail" runat="server" ClientValidationFunction="validateMultipleEmailsCommaSeparated"  ErrorMessage="Invalid email(s)"></asp:CustomValidator>

 <script language="JavaScript" type="text/javascript">

 function validateEmail(field)
 {
     var regex=/^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
     var matchArray=field.match(regex);
     if(matchArray==null)
         return false;
     else
         return true;
 }

 function validateMultipleEmailsCommaSeparated(source, value)
 {
     var result = document.getElementById("<%= txtEmail.ClientID %>").value.split(';');
     for(var i = 0;i < result.length;i++)
     {
         if(!validateEmail(result[i]))
         {
             value.IsValid = false;
             return false;
         }    
     }       
     value.IsValid = true;
 }
 </script>
 
2. Directly defining the regular expression in the RegularExpressionValidator control   
   
    <asp:RegularExpressionValidator ID="s" runat="server" ControlToValidate="txtEmail" ErrorMessage="Invalid email(s)" 
ValidationExpression="(([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)(\s*;\s*|\s*$))*"></asp:RegularExpressionValidator>

Close() Vs Dispose Method

The basic difference between Close() and Dispose() is, when a Close() method is called, any managed resource can be temporarily closed and can be opened once again. It means that, with the same object the resource can be reopened or used. Where as Dispose() method permanently removes any resource ((un)managed) from memory for cleanup and the resource no longer exists for any further processing.
Example showing difference between Close() and Dispose() Method:

using System;
using System.Data;
using System.Data.SqlClient;
public class Test
{
    private string connString = "Data Source=COMP3;Initial Catalog=Northwind;User Id=sa;Password=pass";
    private SqlConnection connection;
    public Test()
    {
        connection = new SqlConnection(connString);
    }
    private static void Main()
    {
        Test t = new Test();
        t.ConnectionStatus();
        Console.ReadLine();
    }
    public void ConnectionStatus()
    {
        try
        {
            if (connection.State == ConnectionState.Closed)
            {
                connection.Open();
                Console.WriteLine("Connection opened..");
            }

            if (connection.State == ConnectionState.Open)
            {
                connection.Close();
                Console.WriteLine("Connection closed..");
            }
            // connection.Dispose();

            if (connection.State == ConnectionState.Closed)
            {
                connection.Open();
                Console.WriteLine("Connection again opened..");
            }
        }
        catch (SqlException ex)
        {
            Console.WriteLine(ex.Message + "\n" + ex.StackTrace);
        }
        catch (Exception ey)
        {
            Console.WriteLine(ey.Message + "\n" + ey.StackTrace);
        }
        finally
        {
            Console.WriteLine("Connection closed and disposed..");
            connection.Dispose();
        }
    }
}

In the above example if you uncomment the "connection.Dispose()" method and execute, you will get an exception as, "The ConnectionString property has not been initialized.".This is the difference between Close() and Dispose().

Make a strongly named assembly with delay sign

Creating Strong Named Assemblies:

Let's see how we can make a strongly named assembly so that we can add it to the GAC folder. The first thing that you need to do is to make the Strong Name this can be done by using the SN.EXE tool. Simply, type the following command on your Visual Studio.NET command prompt.

SN.exe -k MyProject.keys

This will create the MyProject.keys file which will contain the private and public keys. If you are curious and want to see the public key then you can use the SN.EXE tool with a -p switch. Take a look at the line below:

SN.exe -p MyProject.keys MyProject.PublicKey

Now, to view the PublicKey you can use the following line of code:

SN.exe -tp MyProject.PublicKey

Output:

C:\Program Files\Microsoft Visual Studio 9.0\VC>SN.exe -tp c:\MyProject.PublicKe

y

Microsoft (R) .NET Framework Strong Name Utility  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Public key is

0024000004800000940000000602000000240000525341310004000001000100f5e19964891cd7

7c1e9d1c4c600882d1c170bef6360c61654941b43a1fc605b6eca75816f142a6ff3addb760948d

d3b09fc747f32dd2b1ee8d279735f34060e1e00c0e8cb2d1d11ba5ea79257e54bc72229d35b973

a8455b0eb5f8b78189e88da760a26f6694205fafb28d74587133575255d6dee5dfb58c65592544

b34c98d4

Public key token is 11865b32dc3a44cf

You cannot use the SN.exe tool to view the private key.

For delay signing use

[assembly: AssemblyKeyFileAttribute("c:\\MyProject.PublicKey")]

[assembly: AssemblyDelaySignAttribute(true)]

Now after compling the project and if you try to put it in GAC using command below you will find this error:

C:\Program Files\Microsoft Visual Studio 9.0\VC>GACUtil.exe -i c:\StrongClassLib

rary1.dll

Microsoft (R) .NET Global Assembly Cache Utility.  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Failure adding assembly to the cache: Strong name signature could not be verifie

d.  Was the assembly built delay-signed?

So first of all ignore validation of the assembly using command:

C:\Program Files\Microsoft Visual Studio 9.0\VC>SN.exe -Vr C:\StrongClassLibrary

1.dll

Microsoft (R) .NET Framework Strong Name Utility  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Verification entry added for assembly 'StrongClassLibrary1,11865B32DC3A44CF'

This will delay sign theassembly with public key and also ignore validation, so this assembaly can be put in GAC for use using command:

C:\Program Files\Microsoft Visual Studio 9.0\VC>GACUtil.exe -i c:\StrongClassLib

rary1.dll

Microsoft (R) .NET Global Assembly Cache Utility.  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly successfully added to the cache

Now we will sign the Assembly with the strong Key names using –R option and deplay it it GAC as below:

C:\Program Files\Microsoft Visual Studio 9.0\VC>SN.exe -R C:\StrongClassLibrary1

.dll c:\MyProject.keys

Microsoft (R) .NET Framework Strong Name Utility  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly 'C:\StrongClassLibrary1.dll' successfully re-signed

C:\Program Files\Microsoft Visual Studio 9.0\VC>GACUtil.exe -i c:\StrongClassLib

rary1.dll

Microsoft (R) .NET Global Assembly Cache Utility.  Version 3.5.21022.8

Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly successfully added to the cache

Or you can use compiler to do this as below:

Now, to sign the assembly with the strong name you use the following line of code:

csc /keyfile:MyProject.keys Program.cs