ASP.NET Textbox text does not change while trying to update

Question

I have a form where there is a ListBox, a textbox and four buttons called Save, Edit, Delete and Clear. I'm retrieving data from database and populating the ListBox. When I select one of the items in the ListBox, it is populated into the textbox. Now when I delete that item, there is nothing wrong, it works fine. But when I try to update that item, i.e. change the text in the textbox and then click the Edit button, there is problem. In the textbox, I can see the text is being changed, no problem with that, but when I debugged, I found in the backend, the textbox is still containing the old text and not the modified one.

What am I doing wrong?

Here's my UI code:

<asp:Content ID="Content3" ContentPlaceHolderID="MainContent" runat="server">
    <h1>Employee Category</h1>
    <table>
        <td>
            <asp:ListBox ID="listEmployeeCategory" runat="server" Height="164px" Width="210px" AutoPostBack="true" />
        </td>
        <td>
            <table>
                <tr>
                    <td>
                        <asp:Label ID="lblMessage" runat="server" Text="" Visible="false" />
                    </td>
                </tr>
                <tr>
                    <td>
                        <asp:Label ID="lblEmpCategoryName" runat="server" Text="Name: " Font-Bold="true" />
                    </td>
                    <td>
                        <asp:TextBox ID="txtEmpCategoryName" runat="server" />
                    </td>
                    <td>
                        <asp:RequiredFieldValidator ID="rqdEmpCategoryName" ControlToValidate="txtEmpCategoryName" ErrorMessage="Employee Category Name can't be empty!" Style="color:Red" runat="server" />
                    </td>
                </tr>
            </table>
            <asp:Button ID="btnSave" Text="Save" runat="server" OnClick="btnSave_Click" />
            <asp:Button ID="btnEdit" Text="Edit" runat="server" OnClick="btnEdit_Click" />
            <asp:Button ID="btnDelete" Text="Delete" runat="server" OnClick="btnDelete_Click" />
            <asp:Button ID="btnCancel" Text="Cancel" runat="server" />
        </td>
    </table>
</asp:Content> 

And here's my backend code, for the sake of everyone's understanding, I'm posting my entire backend code (except the BL, DAL and DAO codes):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using Shelter.DAO.MasterEntry;
using Shelter.BLL.MasterEntry;

namespace Shelter.UI.MasterEntry
{
    public partial class EmployeeCategoryUI : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                LoadDataIntoListBox();
            }

            else
            {
                if (listEmployeeCategory.SelectedIndex != -1)
                {
                    LoadDataIntoTextBox(Convert.ToInt32(listEmployeeCategory.SelectedValue));  
                }
            }
        }

        private void LoadDataIntoTextBox(int val)
        {
            EmployeeCategory objEmployeeCategory = new EmployeeCategory();
            EmployeeCategoryBLL empCategoryBLL = new EmployeeCategoryBLL();
            objEmployeeCategory.ID = Convert.ToInt32(val);
            DataTable EmpCategoryDt = new DataTable();
            EmpCategoryDt = empCategoryBLL.RetrieveById(objEmployeeCategory);
            txtEmpCategoryName.Text = EmpCategoryDt.Rows[0]["EmpCategoryName"].ToString();
        }

        private void LoadDataIntoListBox()
        {
            EmployeeCategory objEmployeeCategory = new EmployeeCategory();
            EmployeeCategoryBLL empCategoryBLL = new EmployeeCategoryBLL();
            DataSet EmployeeCategoryDs = new DataSet();
            EmployeeCategoryDs = empCategoryBLL.RetreiveFromTable();
            DataTable EmployeeCategoryDt = EmployeeCategoryDs.Tables[0];
            DataRow tempRow = null;
            foreach (DataRow tempRow_Variable in EmployeeCategoryDt.Rows)
            {
                tempRow = tempRow_Variable;
                string rowText = tempRow["EmpCategoryName"] + "(" + tempRow["ID"] + ")";
                string rowValue = tempRow["ID"].ToString();
                listEmployeeCategory.Items.Add(new ListItem(rowText, rowValue));
            }
        }

        protected void btnSave_Click(object sender, EventArgs e)
        {
            EmployeeCategory objEmployeeCategory = new EmployeeCategory();
            EmployeeCategoryBLL empCategoryBLL = new EmployeeCategoryBLL();
            objEmployeeCategory.EmpCategoryName = txtEmpCategoryName.Text;
            bool isSave = empCategoryBLL.SaveToTable(objEmployeeCategory);

            if (isSave)
            {
                int id = empCategoryBLL.ReturnLastInsertedId();
                lblMessage.Visible = true;
                lblMessage.Style.Add("Color", "Green");
                lblMessage.Text = "Data saved successfully!";
                string rowText = txtEmpCategoryName.Text + "(" +id.ToString()+ ")" ;
                string rowValue = id.ToString();
                listEmployeeCategory.Items.Add(new ListItem(rowText, rowValue));
                txtEmpCategoryName.Text = "";
            }

            else 
            {
                lblMessage.Visible = true;
                lblMessage.Style.Add("Color", "Red");
                lblMessage.Text = "Data saving failed!";
            }
        }

        protected void btnEdit_Click(object sender, EventArgs e)
        {
            if (IsPostBack)
            {
                EmployeeCategory objEmployeeCategory = new EmployeeCategory();
                EmployeeCategoryBLL empCategoryBLL = new EmployeeCategoryBLL();
                objEmployeeCategory.EmpCategoryName = txtEmpCategoryName.Text;
                objEmployeeCategory.ID = Convert.ToInt32(listEmployeeCategory.SelectedValue);

                bool isEdit = empCategoryBLL.EditInTable(objEmployeeCategory);
                if (isEdit)
                {
                    int id = objEmployeeCategory.ID;
                    lblMessage.Visible = true;
                    lblMessage.Style.Add("Color", "Green");
                    lblMessage.Text = "Data edited successfully!";
                }
                else
                {
                    lblMessage.Visible = true;
                    lblMessage.Style.Add("Color", "Red");
                    lblMessage.Text = "Data editing failed!";
                }
            }
        }

        protected void btnDelete_Click(object sender, EventArgs e)
        {
            if (IsPostBack)
            {
                EmployeeCategory objEmployeeCategory = new EmployeeCategory();
                EmployeeCategoryBLL empCategoryBLL = new EmployeeCategoryBLL();
                objEmployeeCategory.ID = Convert.ToInt32(listEmployeeCategory.SelectedValue);
                bool isDelete = empCategoryBLL.DeleteFromTable(objEmployeeCategory);

                if (isDelete)
                {
                    lblMessage.Visible = true;
                    lblMessage.Style.Add("Color", "Green");
                    lblMessage.Text = "Data deleted successfully!";
                    listEmployeeCategory.Items.Remove(new ListItem(listEmployeeCategory.SelectedItem.Text, listEmployeeCategory.SelectedValue));
                    txtEmpCategoryName.Text = "";
                }

                else
                {
                    lblMessage.Visible = true;
                    lblMessage.Style.Add("Color", "Red");
                    lblMessage.Text = "Data deleting failed!";
                }
            }
        }
    }
}

The txtEmpCategoryName.Text is still containing the old value, so whenever I try to update, it only takes the old value and not the modified value in the textbox. It seems that the TextChanged event is not working. What is the fix to this problem?

Answer 1

You can use Entity frame in Visual studio;

1. right click on your solution - select new Add - then New Project - C# -Class Library give it a project name and Click Ok to add a new project to your existing project.
2. rename your class to a meaning name such as BusinessLogic and make it public.
3. right click on the newly added project and select add new item, on your popup windows select data on the right panel then select ADO.NET Entity Data Model rename your edmx to a meaningful name and click on add. default option and click on next, point to your SQL database by clicking on the new Connection.

4. select your store procedure for populating your listbox and updating the description and click on Finish.

   CREATE PROCEDURE Proc_name AS BEGIN SET NOCOUNT ON;

   SELECT ID,Description FROM Table_Name END

   CREATE PROCEDURE [dbo].[UpdateEmpCategoryBLL] @ID int, @Description varchar(50) AS BEGIN SET NOCOUNT ON; UPDATE Question1 SET Description = @Description WHERE ID = @ID END

5. In your class Implement your methods for populating listbox and updating the description

   public class Wrapper { public static List EmployeeCategory() { try { return new LOOKUPEntities().empCategoryBLL().ToList(); } catch (Exception) { throw; } }

       public static void UpdateEmpCategory(int id, string description)
       {
           try
           {
               using (LOOKUPEntities client = new LOOKUPEntities())
               {
                   client.UpdateEmpCategoryBLL(id, description);
               }
           }
           catch (Exception)
           {
               throw;
           }
       }
   }
   

   6. copy the connection string from you app.config to your web.config. Then add your class library to your references by right clicking on your references and select add reference, select solution and click on add. Add also System.Data,Entity and click ok.
   7. now;

protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { BindListBox(); } }

protected void BindListBox() { try { ListItem lstBox; listEmployeeCategory.Items.Clear(); var query = Wrapper.EmployeeCategory(); foreach (var items in query) { lstBox = new ListItem(items.Description, items.ID.ToString()); listEmployeeCategory.Items.Add(lstBox); } } catch(Exception ex) { lblMessage.Visible = true; lblMessage.Style.Add("Color", "Red"); lblMessage.Text = "Data loading failed "+ ex +" !"; } }

        protected void listEmployeeCategory_SelectedIndexChanged(object sender, EventArgs e)
        {
            lblMessage.Visible = false;
            try
            {
                Session["ID"] = listEmployeeCategory.SelectedValue.ToString();
                txtEmpCategoryName.Text = listEmployeeCategory.SelectedItem.ToString();

            }
            catch (Exception ex)
            {
                lblMessage.Visible = true;
                lblMessage.Style.Add("Color", "Red");
                lblMessage.Text = "Loading session data failed " + ex + " !";
            }
        }

        protected void btnEdit_Click(object sender, EventArgs e)
        {
            try
            {
                int id = int.Parse(Session["ID"].ToString());
                Wrapper.UpdateEmpCategory(id, txtEmpCategoryName.Text.Trim());
                lblMessage.Visible = true;
                lblMessage.Style.Add("Color", "Green");
                lblMessage.Text = "Data edited successfully!";

                BindListBox();
                txtEmpCategoryName.Text = string.Empty;
            }
            catch
            {
                lblMessage.Visible = true;
                lblMessage.Style.Add("Color", "Red");
                lblMessage.Text = "Data editing failed!";
            }
        }

done!