Create a Comma Separated String from A List of String in asp.net
.cs File Code:

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Web;
  5. using System.Web.UI;
  6. using System.Web.UI.WebControls;
  8. public partial class UserControls_CommaSeparatedControl: System.Web.UI.UserControl {
  9. // Declaring List as static
  11. static List < string > strList = new List < string > ();
  13. protected void Page_Load(object sender, EventArgs e)
  14. {
  15. if (!IsPostBack) {
  16. // Clearing the List ob its first load
  17. strList.Clear();
  18. }
  19. }
  21. protected void BtnSave_Click(object sender, EventArgs e)
  22. {
  23. CreateListOfString();
  24. }
  26. private void CreateListOfString()
  27. {#region--Create list of string--
  29. try
  30. {
  32. if (txtSomeText.Text != "")
  33. {
  34. strList.Add(txtSomeText.Text);
  36. txtSomeText.Text = "";
  37. }
  39. GridView1.DataSource = strList;
  40. GridView1.DataBind();
  42. string Result = GetSeparateTheString(strList, ", ");
  44. LblResult.Text = Result;
  45. }
  46. catch (Exception Exc)
  47. {
  48. LblMessage.Text = "Application Error : " + Exc.Message;
  49. }
  51. #endregion
  53. }
  55. private string GetSeparateTheString(List < string > strList, string comma)
  56. {#region--Create a Comaa Separated string--
  58. try
  59. {
  61. System.Text.StringBuilder sb = new System.Text.StringBuilder();
  63. foreach(string str in strList)
  64. {
  65. // If this statement found any value in the String Builder Object, it will add comma one after another.
  67. if (sb.Length > 0)
  68. {
  69. sb.Append(comma);
  70. }
  72. // in its first pass it will take the first string , then others string: because this line must execute
  74. sb.Append(str);
  75. }
  77. return sb.ToString();
  78. } catch (Exception Exc)
  79. {
  80. LblMessage.Text = "Application Error : " + Exc.Message;
  82. return "";
  83. }
  85. #endregion
  86. }
  87. }