HttpCachePolicy.SetAllowResponseInBrowserHistory(Boolean) 方法

  • 參考

定義

命名空間:
System.Web
組件:
System.Web.dll

當 allow 參數為 true 時，讓回應在用戶端瀏覽器記錄快取中可用，而不考慮伺服器上的 HttpCacheability 設定。

public:
 void SetAllowResponseInBrowserHistory(bool allow);
public void SetAllowResponseInBrowserHistory (bool allow);
member this.SetAllowResponseInBrowserHistory : bool -> unit
Public Sub SetAllowResponseInBrowserHistory (allow As Boolean)

參數

allow
Boolean

true 表示讓用戶端瀏覽器將回應儲存在 [History] 資料夾中，否則為 false。 預設為 false。

範例

下列程式碼範例示範如何覆寫 方法， SetAllowResponseInBrowserHistory 以指示用戶端將其歷程記錄中的回應儲存在自訂 HttpCachePolicy 中。

<%@ Page language="c#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>HttpCachePolicy - SetAllowResponseInBrowserHistory - C# Example</title>
    <script runat="server">
      void Page_Load(Object sender, EventArgs e) 
      {
        // When HttpCacheability is set to NoCache or ServerAndNoCache 
        // the Expires HTTP header is set to -1 by default. This instructs 
        // the client to not cache responses in the History folder. Thus, 
        // each time you use the back/forward buttons, the client requests 
        // a new version of the response. 
        HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.ServerAndNoCache);
        
        // Override the ServerAndNoCache behavior by setting the SetAllowInBrowserHistory 
        // method to true. This directs the client browser to store responses in  
        // its History folder.
        HttpContext.Current.Response.Cache.SetAllowResponseInBrowserHistory(true);
        
        // Display the DateTime value.
        Label1.Text = DateTime.Now.ToLongTimeString();
      }
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>HttpCachePolicy - SetAllowResponseInBrowserHistory - C# Example</h3>
      
      <p>Click the Submit button a few times, and then click the Browser's Back button.<br />
        The page should be stored in the Browser's History folder</p>
        
      <p>Time: <asp:Label id="Label1" runat="server" Font-Bold="True" ForeColor="Red" /></p>
      
      <asp:Button id="Button1" runat="server" Text="Submit" />
    </form>
  </body>
</html>

<%@ Page language="VB" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>HttpCachePolicy - SetAllowResponseInBrowserHistory - Visual Basic .NET Example</title>
    <script runat="server">
      Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) 
          
          ' When HttpCacheability is set to NoCache or ServerAndNoCache 
          ' the Expires HTTP header is set to -1 by default. This instructs 
          ' the client to not cache responses in the History folder. Thus, 
          ' each time you use the back/forward buttons, the client requests 
          ' a new version of the response. 
          HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.ServerAndNoCache)
          
          ' Override the ServerAndNoCache behavior by setting the SetAllowInBrowserHistory 
          ' method to true. This directs the client browser to store responses in  
          ' its History folder.
          HttpContext.Current.Response.Cache.SetAllowResponseInBrowserHistory(True)
          
          ' Display the DateTime value.
          Label1.Text = DateTime.Now.ToLongTimeString()
      End Sub
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>HttpCachePolicy - SetAllowResponseInBrowserHistory - Visual Basic .NET</h3>
      
      <p>Click the Submit button a few times, and then click the Browser's Back button.<br />
        The page should be stored in the Browser's History folder</p>
        
      <p>Time: <asp:Label id="Label1" runat="server" Font-Bold="True" ForeColor="Red" /></p>
      
      <asp:Button id="Button1" runat="server" Text="Submit" />
    </form>
  </body>
</html>

備註

當 HttpCacheability 設定為 NoCache 或 ServerAndNoCacheExpires HTTP 標頭預設設定為 -1 時，這會告知用戶端不要快取 [歷程記錄] 資料夾中的回應，因此當您每次使用 [上一次] 按鈕時，用戶端會要求新版本的回應。 您可以呼叫 方法， SetAllowResponseInBrowserHistory 並將 allow 參數設定為 true ，以覆寫此行為。

如果 HttpCacheability 設定為 或 ServerAndNoCache 以外的 NoCache 值，則 SetAllowResponseInBrowserHistory 呼叫 具有任一值 allow 的方法沒有任何作用。

SetAllowResponseInBrowserHistory.NET Framework 3.5 版引進。 如需詳細資訊，請參閱版本和相依性。

適用於