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

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
}
}