DetailsViewModeEventHandler DetailsViewModeEventHandler DetailsViewModeEventHandler DetailsViewModeEventHandler Delegate

Definizione

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

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

Parametri

sender
Object Object Object Object

Origine dell'evento.The source of the event.

Ereditarietà
DetailsViewModeEventHandlerDetailsViewModeEventHandlerDetailsViewModeEventHandlerDetailsViewModeEventHandler

Esempi

Nell'esempio di codice seguente viene illustrato come aggiungere un DetailsViewModeEventHandler delegato ModeChanging a livello di codice all'evento DetailsView di un controllo.The following code example demonstrates how to programmatically add a DetailsViewModeEventHandler delegate to the ModeChanging 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" };

    // Programmatically register the event-handling method
    // for the ItemInserted event of a DetailsView control.
    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_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {

    // Use the sender parameter to access the DetailsView
    // control that raised the event.
    DetailsView customerDetailsView = (DetailsView)sender;

    // Use the NewMode property to determine the mode to which the 
    // DetailsView control is transitioning.
    switch (e.NewMode)
    {
      case DetailsViewMode.Edit:
        // Hide the pager row and clear the Label control
        // when transitioning to edit mode.
        customerDetailsView.AllowPaging = false;
        MessageLabel.Text = "";
        break;
      case DetailsViewMode.ReadOnly:
        // Display the pager row and confirmation message
        // when transitioning to edit mode.
        customerDetailsView.AllowPaging = true;
        if (e.CancelingEdit)
        {
          MessageLabel.Text = "Update canceled.";
        }
        else
        {
          MessageLabel.Text = "Update completed.";
        }
        break;
      case DetailsViewMode.Insert:
        // Cancel the mode change if the DetailsView
        // control attempts to transition to insert 
        // mode.
        e.Cancel = true;
        break;
      default:
        MessageLabel.Text = "Unsupported mode.";
        break;
    }
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler 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
    
    Dim keyArray() As String = {"CustomerID"}
    customerDetailsView.DataKeyNames = keyArray
    
    ' Programmatically register the event-handling method
    ' for the ItemInserted event of a DetailsView control.
    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_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)

    ' Use the sender parameter to access the DetailsView
    ' control that raised the event.
    Dim customerDetailsView As DetailsView = CType(sender, DetailsView)

    ' Use the NewMode property to determine the mode to which the 
    ' DetailsView control is transitioning.
    Select Case e.NewMode
    
      Case DetailsViewMode.Edit
        ' Hide the pager row and clear the Label control
        ' when transitioning to edit mode.
        customerDetailsView.AllowPaging = False
        MessageLabel.Text = ""

      Case DetailsViewMode.ReadOnly
        ' Display the pager row and confirmation message
        ' when transitioning to edit mode.
        customerDetailsView.AllowPaging = True
        If e.CancelingEdit Then
        
          MessageLabel.Text = "Update canceled."
        
        Else
        
          MessageLabel.Text = "Update completed."
        
        End If

      Case DetailsViewMode.Insert
        ' Cancel the mode change if the DetailsView
        ' control attempts to transition to insert 
        ' mode.
        e.Cancel = True

      Case Else
        MessageLabel.Text = "Unsupported mode."
          
    End Select
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler 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 DetailsViewModeEventHandler ModeChanging in modo dichiarativo un delegato all' DetailsView evento di un controllo.The following code example demonstrates how to declaratively add a DetailsViewModeEventHandler delegate to the ModeChanging 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_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {

    // Use the NewMode property to determine the mode to which the 
    // DetailsView control is transitioning.
    switch (e.NewMode)
    {
      case DetailsViewMode.Edit:
        // Hide the pager row and clear the Label control
        // when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = false;
        MessageLabel.Text = "";
        break;
      case DetailsViewMode.ReadOnly:
        // Display the pager row and confirmation message
        // when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = true;
        if (e.CancelingEdit)
        {
          MessageLabel.Text = "Update canceled.";
        }
        else
        {
          MessageLabel.Text = "Update completed.";
        }
        break;
      case DetailsViewMode.Insert:
        // Cancel the mode change if the DetailsView
        // control attempts to transition to insert 
        // mode.
        e.Cancel = true;
        break;
      default:
        MessageLabel.Text = "Unsupported mode.";
        break;
    }
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
                
      <asp:detailsview id="CustomerDetailsView"
        datasourceid="DetailsViewSource"
        datakeynames="CustomerID"
        autogeneraterows="true"
        autogenerateeditbutton="true" 
        allowpaging="true"
        onmodechanging="CustomerDetailsView_ModeChanging" 
        runat="server">

      </asp:detailsview>
      
      <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" autoeventwireup="false" %>

<!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_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging

    ' Use the NewMode property to determine the mode to which the 
    ' DetailsView control is transitioning.
    Select Case e.NewMode
    
      Case DetailsViewMode.Edit
        ' Hide the pager row and clear the Label control
        ' when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = False
        MessageLabel.Text = ""

      Case DetailsViewMode.ReadOnly
        ' Display the pager row and confirmation message
        ' when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = True
        If e.CancelingEdit Then
        
          MessageLabel.Text = "Update canceled."
        
        Else
        
          MessageLabel.Text = "Update completed."
        
        End If

      Case DetailsViewMode.Insert
        ' Cancel the mode change if the DetailsView
        ' control attempts to transition to insert 
        ' mode.
        e.Cancel = True

      Case Else
        MessageLabel.Text = "Unsupported mode."
          
    End Select
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
                
      <asp:detailsview id="CustomerDetailsView"
        datasourceid="DetailsViewSource"
        datakeynames="CustomerID"
        autogeneraterows="true"
        autogenerateeditbutton="true" 
        allowpaging="true"
        runat="server">

      </asp:detailsview>
      
      <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>

Commenti

L' ModeChanging evento viene generato quando un DetailsView controllo tenta di cambiare la modalità di modifica, inserimento e sola lettura, ma prima che la modalità venga effettivamente modificata.The ModeChanging event is raised when a DetailsView control attempts to change between edit, insert, and read-only mode, but before the mode actually changes. Questo consente di fornire un gestore eventi che esegue una routine personalizzata, ad esempio la configurazione del DetailsView controllo per una modalità specifica o l'annullamento della modifica della modalità, ogni volta che si verifica questo evento.This allows you to provide an event handler that performs a custom routine, such as configuring the DetailsView control for a specific mode or canceling the mode change, whenever this event occurs.

Quando si crea un delegato DetailsViewModeEventHandler, si identifica il metodo che gestirà l'evento.When you create a DetailsViewModeEventHandler 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