HOW TO：以程式設計方式存取 ASP.NET 組態設定
更新：2007 年 11 月
您可以從 ASP.NET 應用程式或 .NET 用戶端應用程式內存取執行階段組態設定。每個組態區段都擁有本身的物件型別，以 C# 而言，在呼叫 WebConfigurationManager 類別的方法時，需要進行轉型 (Casting)。如需與組態區段相關之物件型別的詳細資訊，請參閱 ASP.NET 組態設定參考主題中項目資訊表的區段處理常式。
這個主題中的程式碼範例會使用非靜態方法取得組態資料。這可讓您從任何應用程式取得組態資訊。如果您要從程式碼所在的應用程式中取得組態資訊，請使用靜態 GetSection 方法，這樣處理速度較快。如需詳細資訊，請參閱 ASP.NET 組態 API 概觀中的＜使用本機和遠端組態設定＞章節。
範例
下列的程式碼範例讀取針對 MyAppRoot 應用程式所設定的 identity 項目的 impersonate 屬性 (Attribute) 值。這個值會顯示在 Web 網頁上。程式碼會使用 IdentitySection 物件型別讀取 identity 區段中的資料。
若要更新組態設定，請使用組態物件的 Save 或 SaveAs 方法。如需詳細資訊，請參閱使用組態類別。
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Web.Configuration" %>
<%@ Import Namespace="System.Configuration" %>
<%@ Import Namespace="System.Text" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script >
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
' Set the root path of the Web application that contains the
' Web.config file that you want to access.
Dim configPath As String = "/MyAppRoot"
' Get the configuration object to access the related Web.config file.
Dim config As Configuration = WebConfigurationManager.OpenWebConfiguration(configPath)
' Get the object related to the <identity> section.
Dim section As New IdentitySection
section = config.GetSection("system.web/identity")
' Read the <identity> section.
Dim identity As New StringBuilder
identity.Append("Impersonate: ")
identity.Append(section.Impersonate.ToString())
' Display the <identity> information.
ConfigId.Text = identity.ToString()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Read Configuration Settings</title>
</head>
<body>
<h2>
Read ASP.NET Configuration</h2>
<p>
This page displays the value of the <b>Impersonate</b> attribute of the <b>identity</b>
section of an ASP.NET configuration.
</p>
<h3>
Results</h3>
<p>
<asp:Label ID="ConfigId" BackColor="#dcdcdc" BorderWidth="1" runat="Server" /></p>
</body>
</html>
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Configuration" %>
<%@ Import Namespace="System.Configuration" %>
<%@ Import Namespace="System.Text" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script language="C#" >
public void Page_Load()
{
try
{
// Set the root path of the Web application that contains the
// Web.config file that you want to access.
string configPath = "/MyAppRoot";
// Get the configuration object to access the related Web.config file.
Configuration config = WebConfigurationManager.OpenWebConfiguration(configPath);
// Get the object related to the <identity> section.
IdentitySection section =
(IdentitySection)config.GetSection("system.web/identity");
// Read the <identity> section.
StringBuilder identity = new StringBuilder();
identity.Append("Impersonate: ");
identity.Append(section.Impersonate.ToString());
// Display the <identity> information.
ConfigId.Text = identity.ToString();
}
catch (Exception e)
{
ConfigId.Text = e.ToString();
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Read Configuration Settings</title>
</head>
<body>
<h2>
Read ASP.NET Configuration</h2>
<p>
This page displays the value of the <b>Impersonate</b> attribute of the <b>identity</b>
section of an ASP.NET configuration.
</p>
<h3>
Results</h3>
<p>
<asp:Label ID="ConfigId" BackColor="#dcdcdc" BorderWidth="1" runat="Server" /></p>
</body>
</html>