Page.EnableViewState Propiedad

Definición

Obtiene o establece un valor que indica si la página debe mantener su estado de vista y el de los controles de servidor que contenga cuando finalice la solicitud de página actual.Gets or sets a value indicating whether the page maintains its view state, and the view state of any server controls it contains, when the current page request ends.

public:
 virtual property bool EnableViewState { bool get(); void set(bool value); };
[System.ComponentModel.Browsable(false)]
public override bool EnableViewState { get; set; }
member this.EnableViewState : bool with get, set
Public Overrides Property EnableViewState As Boolean

Valor de propiedad

Es true si la página mantiene su estado de vista; en caso contrario, es false.true if the page maintains its view state; otherwise, false. De manera predeterminada, es true.The default is true.

Atributos

Ejemplos

En el ejemplo de código siguiente se establece la propiedad EnableViewState en false cuando se carga la página.The following code example sets the EnableViewState property to false when the page is loaded. Esto deshabilita el estado de vista del objeto Page, lo que significa que no se guarda la información de estado de vista de la página ni los controles contenidos en la página.This disables view state for the Page object, meaning that neither view-state information for the page nor any controls contained by the page are saved.

Importante

Este ejemplo tiene un cuadro de texto que acepta datos proporcionados por el usuario, lo que puede suponer una amenaza para la seguridad.This example has a text box that accepts user input, which is a potential security threat. De forma predeterminada, ASP.NET Web Pages valida que los datos proporcionados por el usuario no incluyen elementos HTML ni de script.By default, ASP.NET Web pages validate that user input does not include script or HTML elements. Para más información, consulte Información general sobre los ataques mediante scripts.For more information, see Script Exploits Overview.

public class WebPage : Page
{
   private MyForm myFormObj;
   private Label label1;
   private Label label2;
   private TextBox textBoxObj;
   private Button buttonObj;

   public WebPage()
   {
      Page.Init += new System.EventHandler(Page_Init);
   }

   private void Page_Load(object sender, System.EventArgs e)
   {
      // Comment the following line to maintain page view state.
      Page.EnableViewState = false;
      myFormObj.Method = "post";
      Controls.Add(myFormObj);
      textBoxObj.Text = "Welcome to .NET";

      label1.Text = "Enter a name";
      buttonObj.Text = "ClickMe";
      buttonObj.Click += new EventHandler(Button_Click);
      myFormObj.Controls.Add(label1);
      myFormObj.Controls.Add(textBoxObj);
      myFormObj.Controls.Add(buttonObj);
      myFormObj.Controls.Add(label2);
   }
   private void Button_Click(object sender, EventArgs e)
   {
      String temp = "<br>Name is " + textBoxObj.Text + "<br>";
      temp += "Saved content of previous page is " + ViewState["name"] as String;
      label2.Text = temp;
   }
   protected override void LoadViewState(object viewState)
   {
      if(viewState != null)
         base.LoadViewState(viewState);
   }
   protected override object SaveViewState()
   {
      ViewState["name"] = textBoxObj.Text;
      return base.SaveViewState();
   }
   private void Page_Init(object sender, EventArgs e)
   {
      this.Load += new System.EventHandler(this.Page_Load);

      myFormObj = new MyForm();
      label1 = new Label();
      label2 = new Label();
      textBoxObj = new TextBox();
      buttonObj = new Button();
   }
};
Public Class WebPage
   Inherits System.Web.UI.Page
   Private myFormObj As MyForm
   Private label1 As Label
   Private label2 As Label
   Private textBoxObj As TextBox
   Private buttonObj As Button
   
   Public Sub New()
      AddHandler Page.Init, AddressOf Page_Init
   End Sub
   
   
   Private Sub Page_Load(sender As Object, e As System.EventArgs)
      ' Comment the following line to maintain page view state.
      Page.EnableViewState = false
      myFormObj.Method = "post"
      Controls.Add(myFormObj)
      textBoxObj.Text = "Welcome to .NET"
      
      label1.Text = "Enter a name"
      buttonObj.Text = "ClickMe"
      AddHandler buttonObj.Click, AddressOf Button_Click
      myFormObj.Controls.Add(label1)
      myFormObj.Controls.Add(textBoxObj)
      myFormObj.Controls.Add(buttonObj)
      myFormObj.Controls.Add(label2)
   End Sub
   
   Private Sub Button_Click(sender As Object, e As EventArgs)
      Dim temp As [String] = "<br>Name is " + textBoxObj.Text + "<br>"
      temp += "Saved content of previous page is " + CType(ViewState("name"), String)
      label2.Text = temp
   End Sub
   
   Protected Overrides Sub LoadViewState(viewState As Object)
      If Not (viewState Is Nothing) Then
         MyBase.LoadViewState(viewState)
      End If
   End Sub
   
   Protected Overrides Function SaveViewState() As Object
      ViewState("name") = textBoxObj.Text
      Return MyBase.SaveViewState()
   End Function 'SaveViewState
   
   Private Sub Page_Init(sender As Object, e As EventArgs)
      AddHandler Me.Load, AddressOf Me.Page_Load
      myFormObj = New MyForm()
      label1 = New Label()
      label2 = New Label()
      textBoxObj = New TextBox()
      buttonObj = New Button()
   End Sub
End Class

Comentarios

Para obtener información sobre por qué podría querer deshabilitar el estado de vista, consulte Control.EnableViewState.For information about why you might want to disable view state, see Control.EnableViewState.

Aunque EnableViewState sea false, es posible que la página contenga un campo de estado de vista oculto usado por ASP.NET para detectar un postback.Even if EnableViewState is false, the page might contain a hidden view state field that is used by ASP.NET to detect a postback.

Se aplica a

Consulte también: