How to Add Connection String Using Class in C#

Step 1: Create a Class.
             Name it MyClass.cs

Step 2: Write Code which is given below:

             //Include two namespaces..
             using System.Data;
             using System.Data.SqlClient;
             public Static SqlConnection conn()
             {
                  SqlConnection con = new SqlConnection ("Your Connection
                  String");
                  return con;
             }

Step 3: Go to Form where you want to access this string..
            And Write code as given below:

            //You must include above two namespaces..
             using System.Data;
             using System.Data.SqlClient;
             SqlConnection con = MyConnection.conn();
             

How to add connection string in c sharp:

// Add this to namespace in form..

using System.Data;                      

using System.Data.SqlClient;

SqlConnection cn = new SqlConnection("Your Connection String");