Editable DataGrid without link buttons

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• Download design diagram - 29.3 Kb

Introduction

This article explains how to make an ASP.NET editable DataGrid.

Using the code

This a web application with a virtual directory named as EditGrid. You may create the same virtual directory to run this application by VS.NET 2003, or create any other virtual directory and map the path to this directory to access it from the browser. As I have used Access 2002 as my database, you need to have MS Access installed on your machine.

Important Sections of this application

1. DataGrid with TextBox and DataGrid as item templates for enable editing, and two buttons, one for adding a new row to the grid and another for saving the grid data to the database.

   <table class="TABLE_MAIN_NEW" width="100%" ID="Table1">
   <!--tab 3 Starts-->
     <tr vAlign="top">
      <td colSpan="4"></td>
      <td align="right"><asp:button id="btnAdd" runat="server" 
          CausesValidation="False" Text="Add" Width="91px" Height="22"
          CssClass="BUTTON_MEDIUM"></asp:button>
      </td>
     </tr>
     <tr vAlign="top">
      <td align="center" colSpan="5">
       <div class="dgrStyle_new">
       <asp:datagrid id="dgEditGrid" runat="server" 
          CssClass="DGR_MAIN" AutoGenerateColumns="False" width="100%">
            <AlternatingItemStyle CssClass="DGR_ALTERNATE"></AlternatingItemStyle>
            <ItemStyle CssClass="DGR_ITEM"></ItemStyle>
            <HeaderStyle CssClass="DGR_HEADER"></HeaderStyle>
            <Columns>
               <asp:TemplateColumn HeaderText="Description">
                <ItemTemplate>
                  <asp:TextBox MaxLength="50" runat="server" 
                      ID="txtDESCRIPTION" cssclass="TEXTBOX_MEDIUM_DG1" 
                      Text='<%#Container.DataItem("DESCRIPTION")%>' />
                </ItemTemplate>
               </asp:TemplateColumn>
               <asp:TemplateColumn HeaderText="Drop Down">
                <ItemTemplate>
                 <asp:DropDownList id="ddlDrop" runat="server" 
                  Width="100px" cssclass="DROPDOWN_SMALL_DG"></asp:DropDownList>
                </ItemTemplate>
               </asp:TemplateColumn>
               <asp:BoundColumn DataField="itemNumber" HeaderText="Item_No" 
                                         Visible="False"></asp:BoundColumn>
            </Columns>
       </asp:datagrid>
       </div>
      </td>
     </tr>
     <tr vAlign="top">
      <td colSpan="4"></td>
      <td align="right">
         <asp:button id="btnSave" runat="server" 
            CausesValidation="False" Text="Save" Width="91px" Height="22"
            CssClass="BUTTON_MEDIUM">
         </asp:button>
      </td>
     </tr>
   </table>

2. Load routine for loading data to a DataSet from the database.

   Private Sub LoadFile()
   
       Dim con As OleDbConnection
       Dim dtaAdapter As OleDbDataAdapter
       Dim dstCopy As New DataSet
   
       Try
           Dim strPath As String = Server.MapPath("Data") & "\Auto.mdb"
   
           con = New System.Data.OleDb.OleDbConnection("provider=" & _ 
                 "Microsoft.Jet.OLEDB.4.0; " & "data source=" & strPath)
           dtaAdapter = New OleDbDataAdapter("Select * from Table1", con)
           dtaAdapter.Fill(dstCopy, "tbl_Temp_Data")
           con.Close()
           Session.Add("TempData", dstCopy)
           dgEditGrid.DataSource = dstCopy.Tables(0)
           dgEditGrid.DataBind()
   
       Catch ex As Exception
               Throw ex
       End Try
   End Sub

3. BindDrop routine for loading data from DataSet to grid.

   Private Sub BindDrop()
       If Not IsNothing(Session("TempData")) Then
           dstTempData = Session("TempData")
           If Not IsNothing(dstTempData.Tables(0)) _
                   AndAlso dstTempData.Tables(0).Rows.Count > 0 Then
               dgEditGrid.DataSource = dstTempData.Tables(0)
               dgEditGrid.DataBind()
           End If
       End If
   End Sub

4. Add button Click event for adding a new row to the DataSet, there by adding a new row to the grid.

   Private Sub btnAdd_Click(ByVal sender As Object, _
                    ByVal e As System.EventArgs) Handles btnAdd.Click
       Try
   
           If Not IsNothing(Session("TempData")) Then
               dstTempData = Session("TempData")
               Dim drwRow As DataRow
               Dim intPreRow As Integer
               intPreRow = dstTempData.Tables(0).Rows.Count
               '///////////////
   
   
               Dim dgItem As DataGridItem
               For Each dgItem In dgEditGrid.Items
                   Dim intRow As Integer = dgItem.ItemIndex
                   If intRow <> -1 Then
   
                       Dim txtDescription As TextBox = _
                         CType(dgItem.Cells(0).FindControl("txtDESCRIPTION"), _
                         TextBox)
                       Dim ddlDGDrop As DropDownList = _
                         CType(dgItem.Cells(1).FindControl("ddlDrop"), _
                         DropDownList)
                       dstTempData.Tables(0).Rows(intRow)("DESCRIPTION")_
                                                    = txtDescription.Text
                       dstTempData.Tables(0).Rows(intRow)("Type")_
                                         = ddlDGDrop.SelectedValue
   
                   End If
               Next
   
               '//////////////
   
   
               Dim intFinalRow As Integer
               drwRow = dstTempData.Tables(0).NewRow()
               dstTempData.Tables(0).Rows.Add(drwRow)
               intFinalRow = dstTempData.Tables(0).Rows.Count - 1
   
               dstTempData.Tables(0).Rows(intFinalRow)("DESCRIPTION") = ""
               dstTempData.Tables(0).Rows(intFinalRow)("Type") = ""
               Session("TempData") = dstTempData
               BindDrop()
   
           End If
   
       Catch objException As Exception
           Finally
       End Try
   End Sub

5. Save button Click event for saving data from grid to the database.

   Private Sub btnSave_Click(ByVal sender As Object, _
               ByVal e As System.EventArgs) Handles btnSave.Click
       Dim con As OleDbConnection
       Dim dtaAdapter As OleDbDataAdapter
       Dim dstCopy As New DataSet
       Dim cmdGrid As OleDbCommand
       Dim strQuery As String
   
       Dim intError As Integer = 0
       Dim strPath As String = Server.MapPath("Data") & "\Auto.mdb"
   
       con = New System.Data.OleDb.OleDbConnection("provider" & _
             "=Microsoft.Jet.OLEDB.4.0; " & "data source=" & strPath)
       con.Open()
       Dim dgItem As DataGridItem
       For Each dgItem In dgEditGrid.Items
           Dim txtDesc As TextBox = _
             CType(dgItem.Cells(0).FindControl("txtDESCRIPTION"), TextBox)
           Dim ddlType As DropDownList = _
             CType(dgItem.Cells(1).FindControl("ddlDrop"), DropDownList)
           Dim item As Integer
           If txtDesc.Text.Trim <> String.Empty And _
                   ddlType.SelectedItem.Text <> "-Select-" Then
               If IsNumeric(dgItem.Cells(2).Text) Then
                   item = CInt(dgItem.Cells(2).Text)
                   strQuery = "Update Table1 SET DESCRIPTION='" + txtDesc.Text _
                              + "',TYPE='" + ddlType.SelectedItem.Text + _
                              "' WHERE itemNumber=" + CStr(item)
               Else
                   item = 0
                   strQuery = "INSERT INTO Table1(DESCRIPTION,TYPE) VALUES('" _
                              + txtDesc.Text + "','" + _
                              ddlType.SelectedItem.Text + "')"
               End If
               cmdGrid = New OleDbCommand(strQuery, con)
               cmdGrid.ExecuteNonQuery()
               strQuery = String.Empty
               cmdGrid.Dispose()
           End If
       Next
   
       con.Close()
       LoadFile()
   End Sub

6. BindListControls routine for populating data in the dropdown list.

   Private Sub BindListControls(ByRef ddlDrop As DropDownList)
       Dim lstType As ListItem
       lstType = New ListItem("-Select-", "-Select-")
       ddlDrop.Items.Insert(0, lstType)
       lstType = New ListItem("Car", "Car")
       ddlDrop.Items.Insert(1, lstType)
       lstType = New ListItem("Bus", "Bus")
       ddlDrop.Items.Insert(2, lstType)
       lstType = New ListItem("Truck", "Truck")
       ddlDrop.Items.Insert(3, lstType)
       lstType = New ListItem("Bike", "Bike")
       ddlDrop.Items.Insert(4, lstType)
   End Sub

7. DataGrid ItemDataBound event for populating dropdownlists.

   Private Sub dgEditGrid_ItemDataBound(ByVal sender As Object, _
             ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) _
             Handles dgEditGrid.ItemDataBound
       Try
           If e.Item.ItemType = ListItemType.Item Or e.Item.ItemType_
                                  = ListItemType.AlternatingItem Then
               Dim intRow As Integer = e.Item.ItemIndex
               If intRow = -1 Then
                   Exit Sub
               End If
               If Not IsNothing(Session("TempData")) Then
   
                   dstTempData = Session("TempData")
                   Dim CurrentDrop As String = _
                       dstTempData.Tables(0).Rows(intRow)("Type")
                   Dim itemSub As ListItem
                   Dim ddlDGDrop As DropDownList = _
                     CType(e.Item.Cells(1).FindControl("ddlDrop"), DropDownList)
                   BindListControls(ddlDGDrop)
                   itemSub = ddlDGDrop.Items.FindByText(CurrentDrop)
                   If Not itemSub Is Nothing Then itemSub.Selected = True
               End If
           End If
       Catch objException As Exception
           Finally
       End Try
   End Sub

Points of Interest

I found out this method while converting a Lotus Notes application to Windows.