DataGrid.EditItemIndex Property

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets or sets the index of an item in the DataGrid control to edit.

public:
 virtual property int EditItemIndex { int get(); void set(int value); };

public virtual int EditItemIndex { get; set; }

member this.EditItemIndex : int with get, set

Public Overridable Property EditItemIndex As Integer

Property Value

Int32

The index of an item in the DataGrid control to edit. The default value is -1, which indicates that no item in the DataGrid control is being edited.

Exceptions

ArgumentOutOfRangeException

The specified index is less than -1.

Examples

The following code example demonstrates how to use the EditItemIndex property to determine the item selected for editing in the DataGrid control.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script language="C#" runat="server">
 
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
         DataRow dr;
  
         if (Session["ShoppingCart"] == null) 
         {       
 
            Cart.Columns.Add(new DataColumn("Qty", typeof(String)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(String)));
            Session["ShoppingCart"] = Cart;
             
            // Create sample data.
            for (int i = 1; i <= 4; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
                  dr[0] = "2";
               else
                  dr[0] = "1";
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1)).ToString();
               Cart.Rows.Add(dr);
            }
         } 
         else
            Cart = (DataTable)Session["ShoppingCart"];          
 
         CartView = new DataView(Cart);
         CartView.Sort="Item";
 
         if (!IsPostBack)
            BindGrid(); 
                   
      }
 
      void MyDataGrid_Edit(Object sender, DataGridCommandEventArgs e) 
      {
         MyDataGrid.EditItemIndex = e.Item.ItemIndex;
         BindGrid();
      }
 
      void MyDataGrid_Cancel(Object sender, DataGridCommandEventArgs e) 
      {
         MyDataGrid.EditItemIndex = -1;
         BindGrid();
      }
 
      void MyDataGrid_Update(Object sender, DataGridCommandEventArgs e) 
      {
         // For bound columns, the edited value is stored in a TextBox.
         // The TextBox is the 0th element in the column's cell.
         TextBox qtyText = (TextBox)e.Item.Cells[2].Controls[0];
         TextBox priceText = (TextBox)e.Item.Cells[3].Controls[0];
 
         String item = e.Item.Cells[1].Text;
         String qty = qtyText.Text;
         String price = priceText.Text;
        
         DataRow dr;
 
         // With a database, use an update command to update the data. Because 
         // the data source in this example is an in-memory DataTable, delete the 
         // old row and replace it with a new one.
 
         // Remove old entry.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
            CartView.Delete(0);
         CartView.RowFilter = "";
 
         // Add new entry.
         dr = Cart.NewRow();
         dr[0] = qty;
         dr[1] = item;
         dr[2] = price;
         Cart.Rows.Add(dr);
 
         MyDataGrid.EditItemIndex = -1;
         BindGrid();
      }
 
      void BindGrid() 
      {
         MyDataGrid.DataSource = CartView;
         MyDataGrid.DataBind();
      }
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body style="font: 10pt verdana">
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt"
           OnEditCommand="MyDataGrid_Edit"
           OnCancelCommand="MyDataGrid_Cancel"
           OnUpdateCommand="MyDataGrid_Update"
           AutoGenerateColumns="false">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>
 
         <Columns>

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit Command Column">

               <ItemStyle Wrap="false">
               </ItemStyle>

               <HeaderStyle Wrap="false">
               </HeaderStyle>

            </asp:EditCommandColumn>            
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="true" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price" 
                 DataField="Price"/>
 
         </Columns>
 
      </asp:DataGrid>

   </form>
 
</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script language="VB" runat="server">
 
    Dim Cart As New DataTable
    Dim CartView As DataView
    Sub Page_Load(sender As Object, e As EventArgs)
        Dim dr As DataRow
        
        If Session("ShoppingCart") Is Nothing Then
            
            Cart.Columns.Add(New DataColumn("Qty", GetType(String)))
            Cart.Columns.Add(New DataColumn("Item", GetType(String)))
            Cart.Columns.Add(New DataColumn("Price", GetType(String)))
            Session("ShoppingCart") = Cart
            
            ' Create sample data.
            Dim i As Integer
            For i = 1 To 4
                dr = Cart.NewRow()
                If i Mod 2 <> 0 Then
                    dr(0) = "2"
                Else
                    dr(0) = "1"
                End If
                dr(1) = "Item " & i.ToString()
                dr(2) =(1.23 *(i + 1)).ToString()
                Cart.Rows.Add(dr)
            Next i
        Else
            Cart = CType(Session("ShoppingCart"), DataTable)
        End If 
        CartView = New DataView(Cart)
        CartView.Sort = "Item"
        
        If Not IsPostBack Then
            BindGrid()
        End If 
    End Sub 'Page_Load


    Sub MyDataGrid_Edit(sender As Object, e As DataGridCommandEventArgs)
        MyDataGrid.EditItemIndex = e.Item.ItemIndex
        BindGrid()
    End Sub 'MyDataGrid_Edit


    Sub MyDataGrid_Cancel(sender As Object, e As DataGridCommandEventArgs)
        MyDataGrid.EditItemIndex = - 1
        BindGrid()
    End Sub 'MyDataGrid_Cancel


    Sub MyDataGrid_Update(sender As Object, e As DataGridCommandEventArgs)
        ' For bound columns, the edited value is stored in a TextBox.
        ' The TextBox is the 0th element in the column's cell.
        Dim qtyText As TextBox = CType(e.Item.Cells(2).Controls(0), TextBox)
        Dim priceText As TextBox = CType(e.Item.Cells(3).Controls(0), TextBox)
        
        Dim item As String = e.Item.Cells(1).Text
        Dim qty As String = qtyText.Text
        Dim price As String = priceText.Text
        
        Dim dr As DataRow
        
        ' With a database, use an update command to update the data. Because 
        ' the data source in this example is an in-memory DataTable, delete the 
        ' old row and replace it with a new one.
        CartView.RowFilter = "Item='" & item & "'"
        If CartView.Count > 0 Then
            CartView.Delete(0)
        End If
        CartView.RowFilter = ""
        
        ' Add new entry.
        dr = Cart.NewRow()
        dr(0) = qty
        dr(1) = item
        dr(2) = price
        Cart.Rows.Add(dr)
        
        MyDataGrid.EditItemIndex = - 1
        BindGrid()
    End Sub 'MyDataGrid_Update


    Sub BindGrid()
        MyDataGrid.DataSource = CartView
        MyDataGrid.DataBind()
    End Sub 'BindGrid
 
   </script>
 
<head runat="server">
    <title>DataGrid Editing Example</title>
</head>
<body style="font: 10pt verdana">
 
   <form id="form1" runat="server">

      <h3>DataGrid Editing Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt"
           OnEditCommand="MyDataGrid_Edit"
           OnCancelCommand="MyDataGrid_Cancel"
           OnUpdateCommand="MyDataGrid_Update"
           AutoGenerateColumns="false">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>
 
         <Columns>

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update" 
                 HeaderText="Edit Command Column">

               <ItemStyle Wrap="false">
               </ItemStyle>

               <HeaderStyle Wrap="false">
               </HeaderStyle>

            </asp:EditCommandColumn>            
 
            <asp:BoundColumn HeaderText="Item" 
                 ReadOnly="true" 
                 DataField="Item"/>
 
            <asp:BoundColumn HeaderText="Quantity" 
                 DataField="Qty"/>
 
            <asp:BoundColumn HeaderText="Price" 
                 DataField="Price"/>
 
         </Columns>
 
      </asp:DataGrid>

   </form>
 
</body>
</html>

Remarks

Use the EditItemIndex property when the DataGrid control contains an EditCommandColumn to determine the index of the item selected in the DataGrid control to edit.

This property is also used to programmatically control which item is being edited. Setting this property to an index of an item in the DataGrid control will enable editing controls for that item in the EditCommandColumn.

Note

The EditItemIndex property is zero based.

To cancel editing, programmatically set this property to -1.

Caution

Text is not HTML encoded before it is displayed in the DataGrid control. This makes it possible to embed script within HTML tags in the text. If the values for the control come from user input, be sure to validate the values to reduce security vulnerabilities.

Applies to

Udostępnij za pośrednictwem