Null Connectionstring

Question

I write a solution in VS2010 that have some C# and asp.net project in it.

I have a configuration class in C# project to make connectionstring for connect to database and it worked well in C# projects, But when I want to use it in Asp web forms the class return a null connectionstring!!!

Please help me because I can't find anything about this problem in web.

Is that need to write another class and using web.config to make connectionstring for asp projects?? or I can reuse class of C# projects for asp projects??

 protected void Button_Save_Click(object sender, EventArgs e)
    {
        try
        {
            this.intCreatedID = Aryana.Data.Contact.Create(int.Parse(Aryana.Data.FormPublicSetting.GetOption("DefaultGroup"));
        }

///The Method to load data from db(the connectionstring in this method return null

 public static string GetOption(string title)
        {
            using (SqlConnection connection = new SqlConnection(Aryana.Data.Configuration.ConnectionString))
             {
                 using (SqlCommand command = new SqlCommand("SET NOCOUNT OFF SELECT Content FROM [dbo].[DefaultSetting] WHERE (Title = @Title)", connection))
                {
                    command.CommandType = CommandType.Text;

                command.Parameters.AddWithValue("@Title", title);

                connection.Open();

                using (SqlDataReader dr = command.ExecuteReader())
                {
                   if (dr.Read())
                    {
                        string value = (string)dr["Content"];
                        return value;
                    }
                    else
                        throw new ObjectDisposedException("title");
                }

            }
        }
    }

/// The method to make connectionstring

 public static class Configuration
{
    static Configuration()
    {

        string ServerName = Properties.Settings.Default.Server;
        string DataBaseName = Properties.Settings.Default.DataBaseName;

connectionString = "data source=" + ServerName + "; initial catalog=" + DataBaseName + ";user id=sa;";

Answer 1

You can get connection string from web.config file

web.config file:

<configuration>
    <connectionStrings>
       <add name="ConnectionStringName" connectionString="connection string goes here"  />   
    </connectionStrings>
</configuration>

and you can then get the connection string in c# code with:

string connString=ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString;

ConfigurationManager class in is System.Configuration namespace.