HttpSessionState.Remove(String) Méthode

Référence

Définition

Espace de noms:: System.Web.SessionState

Assembly:: System.Web.dll

Important

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Supprime un élément de la collection d’état de session.

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

public void Remove (string name);

member this.Remove : string -> unit

Public Sub Remove (name As String)

Paramètres

name: String

Nom de l’élément à supprimer de la collection d’état de session.

Exemples

L’exemple suivant montre comment stocker des valeurs à l’état de session à l’aide de la Add méthode . Il montre également comment supprimer des valeurs à l’état de session à l’aide de la Remove méthode . Un Repeater contrôle est utilisé pour afficher le contenu de l’état de session sur la page web. La GetEnumerator méthode est utilisée pour itérer dans la collection d’états de session et remplir le Repeater contrôle.

<%@ 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>

Remarques

Si la collection d’état de session ne contient pas d’élément avec le spécifié name, la collection reste inchangée. Aucune exception n’est générée.

S’applique à

Voir aussi

Vue d’ensemble de l’état de session

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