DetailsViewPageEventHandler Delegate

Definition

Represents the method that handles the PageIndexChanging event of a DetailsView control.

C#
public delegate void DetailsViewPageEventHandler(object sender, DetailsViewPageEventArgs e);

Parameters

sender
Object

The source of the event.

e
DetailsViewPageEventArgs

A DetailsViewPageEventArgs that contains the event data.

Examples

The following code example demonstrates how to programmatically add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.

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 Page_Load(Object sender, EventArgs e)
  {

    // Create a new DetailsView object.
    DetailsView customerDetailsView = new DetailsView();

    // Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView";
    customerDetailsView.DataSourceID = "DetailsViewSource";
    customerDetailsView.AutoGenerateRows = true;
    customerDetailsView.AutoGenerateEditButton = true;
    customerDetailsView.AllowPaging = true;
    customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
    customerDetailsView.PagerSettings.Position = PagerPosition.Bottom;

    // Programmatically register the event-handling methods
    // for the DetailsView control.
    customerDetailsView.PageIndexChanging += new DetailsViewPageEventHandler(this.CustomerDetailsView_PageIndexChanging);
    customerDetailsView.ModeChanging += new DetailsViewModeEventHandler(this.CustomerDetailsView_ModeChanging);
    
    // Add the DetailsView object to the Controls collection
    // of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView);

  }
  
  void CustomerDetailsView_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
  {
    // Use the sender parameter to access the DetailsView control
    // that raised the event.
    DetailsView customerDetailsView = (DetailsView)sender;

    // Cancel the paging operation if the DetailsView control 
    // in edit mode.
    if (customerDetailsView.CurrentMode == DetailsViewMode.Edit)
    {
      e.Cancel = true;
      
      // Display an error message.
      int newPage = e.NewPageIndex + 1;
      MessageLabel.Text = "Please update the current record before to moving to page " + 
        newPage.ToString() + ".";
    }
  }

  void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {
    // Clear the message label when the user changes mode.
    MessageLabel.Text = "";
  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewPageEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewPageEventHandler Example</h3>
                               
        <!-- Use a PlaceHolder control as the container for the -->
        <!-- dynamically generated DetailsView control.         -->       
        <asp:placeholder id="DetailsViewPlaceHolder"
          runat="server"/>
          
        <br/><br/>
        
        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>
            
        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the web.config file.                            -->
        <asp:sqldatasource id="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

The following code example demonstrates how to declaratively add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.

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 CustomerDetailsView_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
  {
    // Cancel the paging operation if the DetailsView control 
    // in edit mode.
    if (CustomerDetailsView.CurrentMode == DetailsViewMode.Edit)
    {
      e.Cancel = true;
      
      // Display an error message.
      int newPage = e.NewPageIndex + 1;
      MessageLabel.Text = "Please update the current record before to moving to page " + 
        newPage.ToString() + ".";
    }
  }

  void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {
    // Clear the message label when the user changes mode.
    MessageLabel.Text = "";
  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewPageEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewPageEventHandler Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogenerateeditbutton="true"
          datakeynames="CustomerID"  
          allowpaging="true"
          onpageindexchanging="CustomerDetailsView_PageIndexChanging" 
          onmodechanging="CustomerDetailsView_ModeChanging"
          runat="server">
            
          <pagersettings position="Bottom"/> 
                    
        </asp:detailsview>
        
        <br/>
        
        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>
            
        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the web.config file.                            -->
        <asp:sqldatasource id="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Remarks

The DetailsView control raises the PageIndexChanging event when a pager button (a button with its CommandName property set to "Page") within the control is clicked, but before the DetailsView control handles the paging operation. This allows you to provide an event handler that performs a custom routine, such as canceling the paging operation, whenever this event occurs.

Note

Pager buttons are usually located in the pager row of a DetailsView control.

When you create a DetailsViewPageEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Handling and Raising Events.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.

Applies to

Product Versions
.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