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DetailsView.ItemUpdating Event

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Occurs when an Update button within a DetailsView control is clicked, but before the update operation.

C# 
public event System.Web.UI.WebControls.DetailsViewUpdateEventHandler ItemUpdating;

Event Type

DetailsViewUpdateEventHandler

Examples

The following code example demonstrates how to use the ItemUpdating event to HTML-encode the values entered by the user before a record is updated in the data source.

ASP.NET (C#) 

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  void CustomerDetail_ItemInserted(object sender, 
    DetailsViewInsertedEventArgs e)
  {
    // Refresh the GridView control after a new record is inserted 
    // in the DetailsView control.
    CustomersView.DataBind();
  }

  void CustomerDetail_ItemInserting(object sender, 
    DetailsViewInsertEventArgs e)
  {
    // Iterate though the values entered by the user and HTML encode 
    // the values. This helps prevent malicious values from being 
    // stored in the data source.
    for (int i = 0; i < e.Values.Count; i++)
    {
      if (e.Values[i] != null)
      {
        e.Values[i] = Server.HtmlEncode(e.Values[i].ToString());
      }
    }
  }

  void CustomerDetail_ItemUpdated(object sender, 
    DetailsViewUpdatedEventArgs e)
  {
    // Refresh the GridView control after a new record is updated 
    // in the DetailsView control.
    CustomersView.DataBind();
  }

  void CustomerDetail_ItemUpdating(object sender, 
    DetailsViewUpdateEventArgs e)
  {
    // Iterate though the values entered by the user and HTML encode 
    // the values. This helps prevent malicious values from being 
    // stored in the data source.
    for (int i = 0; i < e.NewValues.Count; i++)
    {
      if (e.NewValues[i] != null)
      {
        e.NewValues[i] = Server.HtmlEncode(e.NewValues[i].ToString());
      }
    }
  }

  void CustomerDetail_ItemDeleted(object sender, 
    DetailsViewDeletedEventArgs e)
  {
    // Refresh the GridView control after a new record is updated 
    // in the DetailsView control.
    CustomersView.DataBind();
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>
      DetailsView Example</title>
</head>
<body>
  <form id="Form1" runat="server">
    <h3>
      DetailsView Example</h3>
    <table cellspacing="10">
      <tr>
        <td>
          <!-- Use a GridView control in combination with      -->
          <!-- a DetailsView control to display master-detail  -->
          <!-- information. When the user selects a store from -->
          <!-- GridView control, the customers//s detailed     -->
          <!-- information is displayed in the DetailsView     -->
          <!-- control.                                        -->
          <asp:GridView ID="CustomersView" DataSourceID="Customers" 
            AutoGenerateColumns="False"
            DataKeyNames="CustomerID" runat="server">
            <HeaderStyle BackColor="Blue" ForeColor="White" />
            <Columns>
              <asp:CommandField ShowSelectButton="True" />
              <asp:BoundField DataField="ContactName" 
                HeaderText="ContactName" />
              <asp:BoundField DataField="CompanyName" 
                HeaderText="CompanyName" />
            </Columns>
          </asp:GridView>
        </td>
        <td valign="top">
          <asp:DetailsView ID="CustomerDetail" 
            DataSourceID="Details" AutoGenerateRows="false"
            AutoGenerateInsertButton="true" 
            AutoGenerateEditButton="true" 
            AutoGenerateDeleteButton="true"
            EmptyDataText="No records." 
            DataKeyNames="CustomerID" GridLines="Both" 
            OnItemInserted="CustomerDetail_ItemInserted"
            OnItemInserting="CustomerDetail_ItemInserting" 
            OnItemUpdated="CustomerDetail_ItemUpdated"
            OnItemUpdating="CustomerDetail_ItemUpdating" 
            OnItemDeleted="CustomerDetail_ItemDeleted"
            runat="server">
            <HeaderStyle BackColor="Navy" ForeColor="White" />
            <RowStyle BackColor="White" />
            <AlternatingRowStyle BackColor="LightGray" />
            <EditRowStyle BackColor="LightCyan" />
            <Fields>
              <asp:BoundField DataField="CustomerID" HeaderText="CustomerID" ReadOnly="True" />
              <asp:BoundField DataField="ContactName" HeaderText="ContactName" />
              <asp:BoundField DataField="ContactTitle" HeaderText="ContactTitle" />
              <asp:BoundField DataField="CompanyName" HeaderText="CompanyName" />
              <asp:BoundField DataField="Address" HeaderText="Address" />
              <asp:BoundField DataField="City" HeaderText="City" />
              <asp:BoundField DataField="Region" HeaderText="Region" />
              <asp:BoundField DataField="PostalCode" HeaderText="PostalCode" />
              <asp:BoundField DataField="Country" HeaderText="Country" />
              <asp:BoundField DataField="Phone" HeaderText="Phone" />
              <asp:BoundField DataField="Fax" HeaderText="Fax" />
            </Fields>
          </asp:DetailsView>
        </td>
      </tr>
    </table>
    <!-- This example uses Microsoft SQL Server and connects -->
    <!-- to the Northwind sample database.                   -->
    <!-- It is strongly recommended that each data-bound     -->
    <!-- control uses a separate data source control.        -->
    <asp:SqlDataSource ID="Customers" runat="server" 
      ConnectionString=
        "<%$ ConnectionStrings:NorthwindConnectionString %>"
      SelectCommand="SELECT [CompanyName], [ContactName], [CustomerID] 
        FROM [Customers]">
    </asp:SqlDataSource>
    <!-- Add a filter to the data source control for the     -->
    <!-- DetailsView control to display the details of the   -->
    <!-- store selected in the GridView control.             -->
    <asp:SqlDataSource ID="Details" 
      ConnectionString=
        "<%$ ConnectionStrings:NorthwindConnectionString %>"
      runat="server" 
      SelectCommand="SELECT * FROM [Customers] 
        WHERE ([CustomerID] = @CustomerID)"
      DeleteCommand="DELETE FROM [Customers] 
        WHERE [CustomerID] = @CustomerID"
      InsertCommand="INSERT INTO [Customers] ([CustomerID], 
        [CompanyName], [ContactName], [ContactTitle], [Address], 
        [City], [Region], [PostalCode], [Country], [Phone], [Fax]) 
        VALUES (@CustomerID, @CompanyName, @ContactName, @ContactTitle, 
        @Address, @City, @Region, @PostalCode, @Country, @Phone, @Fax)"
      UpdateCommand="UPDATE [Customers] SET [CompanyName] = @CompanyName, 
        [ContactName] = @ContactName, [ContactTitle] = @ContactTitle, 
        [Address] = @Address, [City] = @City, [Region] = @Region, 
        [PostalCode] = @PostalCode, [Country] = @Country, 
        [Phone] = @Phone, [Fax] = @Fax 
        WHERE [CustomerID] = @CustomerID">
      <SelectParameters>
        <asp:ControlParameter ControlID="CustomersView" 
          Name="CustomerID" PropertyName="SelectedValue"
          Type="String" />
      </SelectParameters>
      <DeleteParameters>
        <asp:Parameter Name="CustomerID" Type="String" />
      </DeleteParameters>
      <UpdateParameters>
        <asp:Parameter Name="CompanyName" Type="String" />
        <asp:Parameter Name="ContactName" Type="String" />
        <asp:Parameter Name="ContactTitle" Type="String" />
        <asp:Parameter Name="Address" Type="String" />
        <asp:Parameter Name="City" Type="String" />
        <asp:Parameter Name="Region" Type="String" />
        <asp:Parameter Name="PostalCode" Type="String" />
        <asp:Parameter Name="Country" Type="String" />
        <asp:Parameter Name="Phone" Type="String" />
        <asp:Parameter Name="Fax" Type="String" />
        <asp:Parameter Name="CustomerID" Type="String" />
      </UpdateParameters>
      <InsertParameters>
        <asp:Parameter Name="CustomerID" Type="String" />
        <asp:Parameter Name="CompanyName" Type="String" />
        <asp:Parameter Name="ContactName" Type="String" />
        <asp:Parameter Name="ContactTitle" Type="String" />
        <asp:Parameter Name="Address" Type="String" />
        <asp:Parameter Name="City" Type="String" />
        <asp:Parameter Name="Region" Type="String" />
        <asp:Parameter Name="PostalCode" Type="String" />
        <asp:Parameter Name="Country" Type="String" />
        <asp:Parameter Name="Phone" Type="String" />
        <asp:Parameter Name="Fax" Type="String" />
      </InsertParameters>
    </asp:SqlDataSource>
  </form>
</body>
</html>

Remarks

The ItemUpdating event is raised when an Update button within a DetailsView control is clicked, but before the update operation. This allows you to provide an event handler that performs a custom routine, such as canceling the update operation, whenever this event occurs.

A DetailsViewUpdateEventArgs object is passed to the event handler, which allows you to determine the index of the record being updated and to indicate that the update operation should be canceled. To cancel the update operation, set the Cancel property to true. You can also manipulate the Keys, OldValues, and NewValues collections, if necessary, before the values are passed to the data source. A common way to use these collections is to HTML-encode the values supplied by the user before they are stored in the data source. This helps to prevent script injection attacks.

For more information about how to handle events, see Handling and Raising Events.

Applies to

Производ Верзије
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also