Create a Comma Separated String from A List of String in ASP.NET

.cs File Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class UserControls_CommaSeparatedControl: System.Web.UI.UserControl {
    // Declaring List as static

    static List < string > strList = new List < string > ();

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack) {
            // Clearing the List ob its first load
            strList.Clear();
        }
    }

    protected void BtnSave_Click(object sender, EventArgs e)
    {
        CreateListOfString();
    }

    private void CreateListOfString()
    {#region--Create list of string--

        try
        {

            if (txtSomeText.Text != "")
            {
                strList.Add(txtSomeText.Text);

                txtSomeText.Text = "";
            }

            GridView1.DataSource = strList;
            GridView1.DataBind();

            string Result = GetSeparateTheString(strList, ", ");

            LblResult.Text = Result;
        }
     catch (Exception Exc)
        {
            LblMessage.Text = "Application Error : " + Exc.Message;
        }

        #endregion

    }

    private string GetSeparateTheString(List < string > strList, string comma)
    {#region--Create a Comaa Separated string--

        try
        {

            System.Text.StringBuilder sb = new System.Text.StringBuilder();

            foreach(string str in strList)
            {
                // If this statement found any value in the String Builder Object, it will add comma one after another.

                if (sb.Length > 0)
                {
                    sb.Append(comma);
                }

                // in its first pass it will take the first string , then others string: because this line must execute

                sb.Append(str);
            }

            return sb.ToString();
        } catch (Exception Exc)
        {
            LblMessage.Text = "Application Error : " + Exc.Message;

            return "";
        }

        #endregion
    }
}