HttpSessionState.Remove(String) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
將項目從工作階段狀態集合刪除。
public:
void Remove(System::String ^ name);public void Remove (string name);member this.Remove : string -> unitPublic Sub Remove (name As String)參數
- name
- String
要從工作階段狀態集合中刪除的項目名稱。
範例
下列範例示範如何使用 方法，將值儲存在會話狀態 Add 中。 它也會示範如何使用 方法來移除會話狀態 Remove 中的值。 Repeater控件可用來在網頁上顯示會話狀態的內容。 方法 GetEnumerator 可用來逐一查看會話狀態集合並填 Repeater 入控件。
<%@ 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>
備註
如果會話狀態集合不包含具有指定 name的專案，則集合會保持不變。 不會擲回任何例外狀況。
