HttpSessionState.Remove(String) Método

Referencia

Definición

Espacio de nombres:: System.Web.SessionState

Ensamblado:: System.Web.dll

Importante

Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.

Agrega un elemento de la colección de estados de sesión.

public:
 void Remove(System::String ^ name);

public void Remove (string name);

member this.Remove : string -> unit

Public Sub Remove (name As String)

Parámetros

name: String

Nombre del elemento que se va a eliminar de la colección de estados de sesión.

Ejemplos

En el ejemplo siguiente se muestra cómo almacenar valores en estado de sesión mediante el Add método . También muestra cómo quitar valores en estado de sesión mediante el Remove método . Se usa un Repeater control para mostrar el contenido del estado de sesión en la página web. El GetEnumerator método se usa para recorrer en iteración la colección de estado de sesión y rellenar el Repeater 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">

    protected void Button1_Click(object sender, EventArgs e)
    {
        // If both name and value are specified
        // use the Add method to add the item to session-state.
        if (!String.IsNullOrEmpty(TextBox1.Text) &
            !String.IsNullOrEmpty(TextBox2.Text))
        {
            string itemName = Server.HtmlEncode(TextBox1.Text);
            string itemValue = Server.HtmlEncode(TextBox2.Text);
            Session.Add(itemName, itemValue);
            // Refresh the Repeater control.
            RefreshRepeater();
        }
    }

    protected void RefreshRepeater()
    {
        // Use the GetEnumerator method to 
        // iterate through the session-state.
        ArrayList values = new ArrayList();
        System.Collections.IEnumerator ie = Session.GetEnumerator();
        string currentSessionItemName;
        while (ie.MoveNext())
        {
            currentSessionItemName = (string)ie.Current;
            values.Add(new SessionDataDisplay(currentSessionItemName,
                Session[currentSessionItemName].ToString()));
            
        }
        // Bind values ArrayList to Repeater control.
        Repeater1.DataSource = values;
        Repeater1.DataBind();
    }
    
    public class SessionDataDisplay
    {
        private string _name;
        private string _value;

        public SessionDataDisplay(string name, string value)
        {
            this._name = name;
            this._value = value;
        }
        public string Name
        {
            get { return _name; }
        }
        public string Value
        {
            get { return _value; }
        }
    }

    protected void Repeater1_ItemCommand(object source, RepeaterCommandEventArgs e)
    {
        // Determine which item to remove and
        // use the Remove method to remove it.
        RepeaterItem itemToRemove = e.Item;
        string sessionItemToRemove = 
            ((Label)itemToRemove.FindControl("Label1")).Text;
        Session.Remove(sessionItemToRemove);
        // Refresh the Repeater control.
        RefreshRepeater();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>HttpSessionState Example</title>
</head>
<body>
    <form id="form1" 
          runat="server" 
          defaultbutton="Button1" 
          defaultfocus="TextBox1">
    <div>
        Name
        <asp:TextBox ID="TextBox1"
                     runat="server"></asp:TextBox>
        <br />
        Value
        <asp:TextBox ID="TextBox2" 
                     runat="server"></asp:TextBox>
        <asp:Button ID="Button1" 
                    runat="server" 
                    OnClick="Button1_Click" 
                    Text="Add" />
        <br />
        <asp:Repeater ID="Repeater1" runat="server" OnItemCommand="Repeater1_ItemCommand">
          <ItemTemplate>
             <br />
                SessionState Item Name:  
                <asp:Label ID="Label1" 
                           runat="server" 
                           Text='<%# DataBinder.Eval(Container.DataItem, "Name") %>'/>,
                SessionState Item Value: 
                <asp:Label ID="Label2" 
                           runat="server" 
                           Text='<%# DataBinder.Eval(Container.DataItem, "Value") %>'/>
                <asp:Button ID="RemoveItem" 
                            Text="Remove" 
                            runat="server" />
          </ItemTemplate>
        </asp:Repeater>
    
    </div>
    </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">

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)

        ' If both name and value are specified
        ' use the Add method to add the item to session-state.
        If (Not String.IsNullOrEmpty(TextBox1.Text) And _
            Not String.IsNullOrEmpty(TextBox2.Text)) Then
            
            Dim itemName As String = Server.HtmlEncode(TextBox1.Text)
            Dim itemValue As String = Server.HtmlEncode(TextBox2.Text)
            Session.Add(itemName, itemValue)
            ' Refresh the Repeater control.
            RefreshRepeater()
            
        End If        
    End Sub
    
    Protected Sub RefreshRepeater()
        
        ' Use the GetEnumerator method to 
        ' iterate through the session-state.
        Dim values As ArrayList = New ArrayList()
        Dim ie As System.Collections.IEnumerator = Session.GetEnumerator()
        Dim currentSessionItemName As String
        While (ie.MoveNext())
            
            currentSessionItemName = CType(ie.Current, String)
            values.Add(New SessionDataDisplay(currentSessionItemName, _
                Session(currentSessionItemName).ToString()))
        End While
        ' Bind values ArrayList to Repeater control.
        Repeater1.DataSource = values
        Repeater1.DataBind()
        
    End Sub
    
    Public Class SessionDataDisplay
        
        Private _name As String
        Private _value As String
        
        Public Sub New(ByVal name As String, ByVal value As String)
            
            Me._name = name
            Me._value = value
            
        End Sub
        Public ReadOnly Property Name() As String
            Get
                Return _name
            End Get
        End Property
        
        Public ReadOnly Property Value() As String
            Get
                Return _value
            End Get
        End Property
        
    End Class

    Protected Sub Repeater1_ItemCommand(ByVal source As Object, _
           ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs)

        ' Determine which item to remove and
        ' use the Remove method to remove it.
        Dim itemToRemove As RepeaterItem = e.Item
        Dim sessionItemToRemove As String = _
            CType(itemToRemove.FindControl("Label1"), Label).Text
        Session.Remove(sessionItemToRemove)
        ' Refresh the Repeater control.
        RefreshRepeater()
    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>HttpSessionState Example</title>
</head>
<body>
    <form id="form1" 
          runat="server" 
          defaultbutton="Button1" 
          defaultfocus="TextBox1">
    <div>
        Name
        <asp:TextBox ID="TextBox1"
                     runat="server"></asp:TextBox>
        <br />
        Value
        <asp:TextBox ID="TextBox2" 
                     runat="server"></asp:TextBox>
        <asp:Button ID="Button1" 
                    runat="server" 
                    OnClick="Button1_Click" 
                    Text="Add" />
        <br />
        <asp:Repeater ID="Repeater1" runat="server" OnItemCommand="Repeater1_ItemCommand">
          <ItemTemplate>
             <br />
                SessionState Item Name:  
                <asp:Label ID="Label1" 
                           runat="server" 
                           Text='<%# DataBinder.Eval(Container.DataItem, "Name") %>'/>,
                SessionState Item Value: 
                <asp:Label ID="Label2" 
                           runat="server" 
                           Text='<%# DataBinder.Eval(Container.DataItem, "Value") %>'/>
                <asp:Button ID="RemoveItem" 
                            Text="Remove" 
                            runat="server" />
          </ItemTemplate>
        </asp:Repeater>
    
    </div>
    </form>
</body>
</html>

Comentarios

Si la colección session-state no contiene un elemento con el especificado name, la colección permanece sin cambios. No se inicia ninguna excepción.

Se aplica a

Consulte también

Información general sobre el estado de sesión

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