FormViewCommandEventArgs FormViewCommandEventArgs FormViewCommandEventArgs FormViewCommandEventArgs Class

Definizione

Fornisce dati per l'evento ItemCommand.Provides data for the ItemCommand event.

public ref class FormViewCommandEventArgs : System::Web::UI::WebControls::CommandEventArgs
public class FormViewCommandEventArgs : System.Web.UI.WebControls.CommandEventArgs
type FormViewCommandEventArgs = class
    inherit CommandEventArgs
Public Class FormViewCommandEventArgs
Inherits CommandEventArgs
Ereditarietà
FormViewCommandEventArgsFormViewCommandEventArgsFormViewCommandEventArgsFormViewCommandEventArgs

Esempi

Nell'esempio seguente viene illustrato come utilizzare l' FormViewCommandEventArgs oggetto passato al metodo di gestione degli eventi per l' ItemCommand evento per determinare quale pulsante all'interno FormView di un controllo è stato fatto clic dall'utente.The following example demonstrates how to use the FormViewCommandEventArgs object passed to the event-handling method for the ItemCommand event to determine which button within a FormView control was clicked by the user.

Importante

L'esempio include una casella di testo che accetta l'input dell'utente e rappresenta quindi una potenziale minaccia alla sicurezza.This example has a text box that accepts user input, which is a potential security threat. Per impostazione predefinita, le pagine Web ASP.NET verificano che l'input dell'utente non includa script o elementi HTML.By default, ASP.NET Web pages validate that user input does not include script or HTML elements. Per altre informazioni, vedere Cenni preliminari sugli attacchi tramite script.For more information, see Script Exploits Overview.


<%@ 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 ProductFormView_ItemCommand(Object sender, FormViewCommandEventArgs e)
  {

    // The ItemCommand event is raised when any button within
    // the FormView control is clicked. Use the CommandName property 
    // to determine which button was clicked. 
    if (e.CommandName == "Add")
    {

      // Add the product to the ListBox control. 
      
      // Use the Row property to retrieve the data row.
      FormViewRow row = ProductFormView.Row;
      
      // Retrieve the ProductNameLabel control from
      // the data row.
      Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

      // Retrieve the QuantityTextBox control from
      // the data row.
      TextBox quantityTextBox = (TextBox)row.FindControl("QuantityTextBox");

      if (productNameLabel != null && quantityTextBox != null)
      {    
        // Get the product name from the ProductNameLabel control.
        string name = productNameLabel.Text;
        
        // Get the quantity from the QuantityTextBox control.
        string quantity = quantityTextBox.Text;

        // Create the text to display in the ListBox control.
        string description = name + " - " + quantity + " Qty";

        // Create a ListItem object using the description and
        // product name.
        ListItem item = new ListItem(description, name);

        // Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item);

        // Use the CommandSource property to retrieve
        // the Add button. Disable the button after
        // the user adds the currently displayed employee
        // name to the ListBox control.
        Button addButton = (Button)e.CommandSource;
        addButton.Enabled = false;
      }

    }

  }

  void ProductFormView_DataBound(Object sender, EventArgs e)
  {
    
    // To prevent the user from adding duplicate items, 
    // disable the Add button if the item being bound to the 
    // FormView control is already in the ListBox control.
    
    // Use the Row property to retrieve the data row.
    FormViewRow row = ProductFormView.Row;

    // Retrieve the Add button from the data row.
    Button addButton = (Button)row.FindControl("AddButton");

    // Retrieve the ProductNameLabel control from
    // data row.
    Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

    if (addButton != null && productNameLabel != null)
    {
      // Get the product name from the ProductNameLabel 
      // control.
      string name = productNameLabel.Text;

      // Use the FindByValue method to determine whether
      // the ListBox control already contains an entry for
      // the item.
      ListItem item = ProductListBox.Items.FindByValue(name);

      // Disable the Add button if the ListBox control
      // already contains the item.
      if (item != null)
      {
        addButton.Enabled = false;
      }
      else
      {
        addButton.Enabled = true;
      }
    }

  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        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="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        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 ProductFormView_ItemCommand(ByVal sender As Object, ByVal e As FormViewCommandEventArgs)

    ' The ItemCommand event is raised when any button within
    ' the FormView control is clicked. Use the CommandName property 
    ' to determine which button was clicked. 
    If e.CommandName = "Add" Then

      ' Add the product to the ListBox control. 
      
      ' Use the Row property to retrieve the data row.
      Dim row As FormViewRow = ProductFormView.Row
      
      ' Retrieve the ProductNameLabel control from
      ' the data row.
      Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

      ' Retrieve the QuantityTextBox control from
      ' the data row.
      Dim quantityTextBox As TextBox = CType(row.FindControl("QuantityTextBox"), TextBox)

      If productNameLabel IsNot Nothing And quantityTextBox IsNot Nothing Then
          
        ' Get the product name from the ProductNameLabel control.
        Dim name As String = productNameLabel.Text
        
        ' Get the quantity from the QuantityTextBox control.
        Dim quantity As String = quantityTextBox.Text

        ' Create the text to display in the ListBox control.
        Dim description As String = name & " - " & quantity & " Qty"

        ' Create a ListItem object using the description and
        ' product name.
        Dim item As new ListItem(description, name)

        ' Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item)

        ' Use the CommandSource property to retrieve
        ' the Add button. Disable the button after
        ' the user adds the currently displayed employee
        ' name to the ListBox control.
        Dim addButton As Button = CType(e.CommandSource, Button)
        addButton.Enabled = False
        
      End If

    End If

  End Sub

  Sub ProductFormView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
    
    ' To prevent the user from adding duplicate items, 
    ' disable the Add button if the item being bound to the 
    ' FormView control is already in the ListBox control.
    
    ' Use the Row property to retrieve the data row.
    Dim row As FormViewRow = ProductFormView.Row

    ' Retrieve the Add button from the data row.
    Dim addButton As Button = CType(row.FindControl("AddButton"), Button)

    ' Retrieve the ProductNameLabel control from
    ' data row.
    Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

    If addButton IsNot Nothing And productNameLabel IsNot Nothing Then
    
      ' Get the product name from the ProductNameLabel 
      ' control.
      Dim name As String = productNameLabel.Text

      ' Use the FindByValue method to determine whether
      ' the ListBox control already contains an entry for
      ' the item.
      Dim item As ListItem = ProductListBox.Items.FindByValue(name)

      ' Disable the Add button if the ListBox control
      ' already contains the item.
      If item IsNot Nothing Then
      
        addButton.Enabled = False
      
      Else
      
        addButton.Enabled = True
        
      End If
      
    End If

  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        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="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Commenti

L' ItemCommand evento viene generato quando si fa clic su FormView un pulsante all'interno del controllo.The ItemCommand event is raised when a button within the FormView control is clicked. In questo modo è possibile fornire un metodo di gestione degli eventi che esegua una routine personalizzata ogni volta che si verifica questo evento.This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.

I pulsanti all' FormView interno di un controllo possono anche richiamare alcune delle funzionalità predefinite del controllo.Buttons within a FormView control can also invoke some of the built-in functionality of the control. Per eseguire una di queste operazioni, impostare la CommandName proprietà di un pulsante su uno dei valori indicati nella tabella seguente.To perform one of these operations, set the CommandName property of a button to one of the values in the following table.

Valore CommandNameCommandName value DescriptionDescription
Annullare"Cancel" Annulla un'operazione di modifica o inserimento e restituisce il FormView controllo alla modalità specificata DefaultMode dalla proprietà.Cancels an edit or insert operation and returns the FormView control to the mode specified by the DefaultMode property. Genera gli ModeChanged eventi ModeChanging e.Raises the ModeChanged and ModeChanging events.
"Delete""Delete" Elimina il record corrente.Deletes the current record. Genera gli ItemDeleted eventi ItemDeleting e.Raises the ItemDeleted and ItemDeleting events.
Modifica"Edit" Inserisce il FormView controllo in modalità di modifica.Puts the FormView control in edit mode. Genera gli ModeChanged eventi ModeChanging e.Raises the ModeChanged and ModeChanging events.
Inserire"Insert" Inserisce il record corrente nell'origine dati.Inserts the current record in the data source. Genera gli ItemInserted eventi ItemInserting e.Raises the ItemInserted and ItemInserting events.
Nuovo"New" Inserisce il FormView controllo in modalità di inserimento.Puts the FormView control in insert mode. Genera gli ModeChanged eventi ModeChanging e.Raises the ModeChanged and ModeChanging events.
Pagina"Page" Esegue un'operazione di paging.Performs a paging operation. Impostare la CommandArgument proprietà del pulsante su "First", "Last", "Next", "prec" o un numero di pagina per specificare il tipo di operazione di paging da eseguire.Set the CommandArgument property of the button to "First", "Last", "Next", "Prev", or a page number to specify the type of paging operation to perform. Genera gli PageIndexChanged eventi PageIndexChanging e.Raises the PageIndexChanged and PageIndexChanging events.
Aggiornamento"Update" Aggiorna il record corrente nell'origine dati.Updates the current record in the data source. Genera gli ItemUpdated eventi ItemUpdating e.Raises the ItemUpdated and ItemUpdating events.

Sebbene l' ItemCommand evento venga generato quando si fa clic su un pulsante elencato nella tabella precedente, è consigliabile utilizzare gli eventi elencati nella tabella per l'operazione.Although the ItemCommand event is raised when a button listed in the previous table is clicked, it is recommended that you use the events listed in the table for the operation.

Un FormViewCommandEventArgs oggetto viene passato al metodo di gestione degli eventi, che consente di determinare il nome del comando e l'argomento del comando del pulsante selezionato.A FormViewCommandEventArgs object is passed to the event-handling method, which allows you to determine the command name and command argument of the button clicked. Per determinare il nome del comando e l'argomento del comando CommandName , CommandArgument usare rispettivamente le proprietà e.To determine the command name and command argument, use the CommandName and CommandArgument properties, respectively. È anche possibile accedere al controllo Button che ha generato l'evento usando la CommandSource proprietà.You can also access the button control that raised the event by using the CommandSource property.

Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.For more information about how to handle events, see Handling and Raising Events.

Per un elenco dei valori iniziali delle proprietà di un'istanza della classe FormViewCommandEventArgs, vedere il costruttore FormViewCommandEventArgs.For a list of initial property values for an instance of the FormViewCommandEventArgs class, see the FormViewCommandEventArgs constructor.

Costruttori

FormViewCommandEventArgs(Object, CommandEventArgs) FormViewCommandEventArgs(Object, CommandEventArgs) FormViewCommandEventArgs(Object, CommandEventArgs) FormViewCommandEventArgs(Object, CommandEventArgs)

Inizializza una nuova istanza della classe FormViewCommandEventArgs.Initializes a new instance of the FormViewCommandEventArgs class.

Proprietà

CommandArgument CommandArgument CommandArgument CommandArgument

Ottiene l'argomento del comando.Gets the argument for the command.

(Inherited from CommandEventArgs)
CommandName CommandName CommandName CommandName

Ottiene il nome del comando.Gets the name of the command.

(Inherited from CommandEventArgs)
CommandSource CommandSource CommandSource CommandSource

Ottiene il controllo che ha generato l'evento.Gets the control that raised the event.

Handled Handled Handled Handled

Ottiene o imposta un valore che indica se il controllo ha gestito l'evento.Gets or sets a value that indicates whether the control has handled the event.

Metodi

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determina se l'oggetto specificato è uguale all'oggetto corrente.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Funge da funzione hash predefinita.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Ottiene l'oggetto Type dell'istanza corrente.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crea una copia superficiale dell'oggetto Object corrente.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Restituisce una stringa che rappresenta l'oggetto corrente.Returns a string that represents the current object.

(Inherited from Object)

Si applica a

Vedi anche