DetailsViewPageEventHandler DetailsViewPageEventHandler DetailsViewPageEventHandler DetailsViewPageEventHandler Delegate

Definizione

Rappresenta il metodo che gestisce l'evento PageIndexChanging di un controllo DetailsView.Represents the method that handles the PageIndexChanging event of a DetailsView control.

public delegate void DetailsViewPageEventHandler(System::Object ^ sender, DetailsViewPageEventArgs ^ e);
public delegate void DetailsViewPageEventHandler(object sender, DetailsViewPageEventArgs e);
type DetailsViewPageEventHandler = delegate of obj * DetailsViewPageEventArgs -> unit
Public Delegate Sub DetailsViewPageEventHandler(sender As Object, e As DetailsViewPageEventArgs)

Parametri

sender
Object Object Object Object

Origine dell'evento.The source of the event.

Ereditarietà
DetailsViewPageEventHandlerDetailsViewPageEventHandlerDetailsViewPageEventHandlerDetailsViewPageEventHandler

Esempi

Nell'esempio di codice seguente viene illustrato come aggiungere un DetailsViewPageEventHandler delegato PageIndexChanging a livello di codice all'evento DetailsView di un controllo.The following code example demonstrates how to programmatically add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.


<%@ 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>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create a new DetailsView object.
    Dim customerDetailsView As New DetailsView()

    ' Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView"
    customerDetailsView.DataSourceID = "DetailsViewSource"
    customerDetailsView.AutoGenerateRows = True
    customerDetailsView.AutoGenerateEditButton = True
    customerDetailsView.AllowPaging = true
    customerDetailsView.PagerSettings.Position = PagerPosition.Bottom

    Dim keyArray() As String = {"CustomerID"}
    customerDetailsView.DataKeyNames = keyArray
       
    ' Programmatically register the event-handling methods
    ' for the DetailsView control.
    AddHandler customerDetailsView.PageIndexChanging, AddressOf CustomerDetailsView_PageIndexChanging
    AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging
    
    ' Add the DetailsView object to the Controls collection
    ' of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView)

  End Sub
  
  Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs)
  
    ' Use the sender parameter to access the DetailsView control
    ' that raised the event.
    Dim customerDetailsView As DetailsView = CType(sender, DetailsView)

    ' Cancel the paging operation if the DetailsView control 
    ' in edit mode.
    If customerDetailsView.CurrentMode = DetailsViewMode.Edit Then
    
      e.Cancel = True
      
      ' Display an error message.
      Dim newPage As Integer = e.NewPageIndex + 1
      MessageLabel.Text = "Please update the current record before to moving to page " & _
        newPage.ToString() & "."
    
    End If
      
  End Sub

  Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
  
    ' Clear the message label when the user changes mode.
    MessageLabel.Text = ""
  
  End Sub
  
</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>

Nell'esempio di codice seguente viene illustrato come aggiungere DetailsViewPageEventHandler PageIndexChanging in modo dichiarativo un delegato all' DetailsView evento di un controllo.The following code example demonstrates how to declaratively add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.


<%@ 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>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
  Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs) Handles CustomerDetailsView.PageIndexChanging
  
    ' Cancel the paging operation if the DetailsView control 
    ' in edit mode.
    If CustomerDetailsView.CurrentMode = DetailsViewMode.Edit Then
    
      e.Cancel = True
      
      ' Display an error message.
      Dim newPage As Integer = e.NewPageIndex + 1
      MessageLabel.Text = "Please update the current record before to moving to page " & _
        newPage.ToString() & "."
    
    End If
      
  End Sub

  Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging
  
    ' Clear the message label when the user changes mode.
    MessageLabel.Text = ""
      
  End Sub
  
</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"
          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>

Commenti

Il DetailsView controllo genera l' PageIndexChanging evento quando si fa clic su un pulsante del cercapersone CommandName , ovvero un pulsante con la relativa proprietà impostata su "Page", all'interno del DetailsView controllo, ma prima che il controllo gestisca l'operazione di paging.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. Questo consente di fornire un gestore eventi che esegue una routine personalizzata, ad esempio l'annullamento dell'operazione di paging, ogni volta che si verifica questo evento.This allows you to provide an event handler that performs a custom routine, such as canceling the paging operation, whenever this event occurs.

Nota

I pulsanti di spostamento si trovano in genere nella riga del DetailsView cercapersone di un controllo.Pager buttons are usually located in the pager row of a DetailsView control.

Quando si crea un delegato DetailsViewPageEventHandler, si identifica il metodo che gestirà l'evento.When you create a DetailsViewPageEventHandler delegate, you identify the method that will handle the event. Per associare l'evento al gestore eventi in uso, aggiungere all'evento un'istanza del delegato.To associate the event with your event handler, add an instance of the delegate to the event. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non venga rimosso il delegato.The event handler is called whenever the event occurs, unless you remove the delegate. Per ulteriori informazioni sui delegati del gestore eventi, vedere gestione e generazione di eventi.For more information about event-handler delegates, see Handling and Raising Events.

Metodi di estensione

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

Ottiene un oggetto che rappresenta il metodo rappresentato dal delegato specificato.Gets an object that represents the method represented by the specified delegate.

Si applica a

Vedi anche