我們研究了頁面生命周期以及頁面如何包含各種控制項。頁面本身被實例化爲一個控制項對象。所有web窗體基本上都是ASP.NET頁類的實例。page類具有與內部對象相對應的以下非常有用的屬性：
- Session
- Application
- Cache
- Request
- Response
- Server
- User
- Trace
我們將在適當的時候討論每一個目標。在本教程中，我們將探討伺服器對象、請求對象和響應對象。
Server Object
Asp.NET中的伺服器對象是System.Web.HttpServerUtility類的實例。HttpServerUtility類提供了許多屬性和方法來執行各種作業。
Properties and Methods of the Server object
HttpServerUtility類的方法和屬性通過ASP.NET提供的內部伺服器對象公開。
下表提供了屬性列表：
| Property | Description |
|---|---|
| MachineName | Name of server computer |
| ScriptTimeOut | Gets and sets the request time-out value in seconds. |
下表列出了一些重要的方法：
| Method | Description |
|---|---|
| CreateObject(String) | Creates an instance of the COM object identified by its ProgID (Programmatic ID). |
| CreateObject(Type) | Creates an instance of the COM object identified by its Type. |
| Equals(Object) | Determines whether the specified Object is equal to the current Object. |
| Execute(String) | Executes the handler for the specified virtual path in the context of the current request. |
| Execute(String, Boolean) | Executes the handler for the specified virtual path in the context of the current request and specifies whether to clear the QueryString and Form collections. |
| GetLastError | Returns the previous exception. |
| GetType | Gets the Type of the current instance. |
| HtmlEncode | Changes an ordinary string into a string with legal HTML characters. |
| HtmlDecode | Converts an Html string into an ordinary string. |
| ToString | Returns a String that represents the current Object. |
| Transfer(String) | For the current request, terminates execution of the current page and starts execution of a new page by using the specified URL path of the page. |
| UrlDecode | Converts an URL string into an ordinary string. |
| UrlEncodeToken | Works same as UrlEncode, but on a byte array that contains Base64-encoded data. |
| UrlDecodeToken | Works same as UrlDecode, but on a byte array that contains Base64-encoded data. |
| MapPath | Return the physical path that corresponds to a specified virtual file path on the server. |
| Transfer | Transfers execution to another web page in the current application. |
Request Object
請求對象是System.Web.HttpRequest類的實例。它表示將頁面加載到瀏覽器中的HTTP請求的值和屬性。
此對象所呈現的信息由更高級別的抽象（web控制項模型）包裝。但是，此對象有助於檢查某些信息，如客戶端瀏覽器和cookies。
Properties and Methods of the Request Object
下表提供了請求對象的一些值得注意的屬性：
| Property | Description |
|---|---|
| AcceptTypes | Gets a string array of client-supported MIME accept types. |
| ApplicationPath | Gets the ASP.NET application's virtual application root path on the server. |
| Browser | Gets or sets information about the requesting client's browser capabilities. |
| ContentEncoding | Gets or sets the character set of the entity-body. |
| ContentLength | Specifies the length, in bytes, of content sent by the client. |
| ContentType | Gets or sets the MIME content type of the incoming request. |
| Cookies | Gets a collection of cookies sent by the client. |
| FilePath | Gets the virtual path of the current request. |
| Files | Gets the collection of files uploaded by the client, in multipart MIME format. |
| Form | Gets a collection of form variables. |
| Headers | Gets a collection of HTTP headers. |
| HttpMethod | Gets the HTTP data transfer method (such as GET, POST, or HEAD) used by the client. |
| InputStream | Gets the contents of the incoming HTTP entity body. |
| IsSecureConnection | Gets a value indicating whether the HTTP connection uses secure sockets (that is, HTTPS). |
| QueryString | Gets the collection of HTTP query string variables. |
| RawUrl | Gets the raw URL of the current request. |
| RequestType | Gets or sets the HTTP data transfer method (GET or POST) used by the client. |
| ServerVariables | Gets a collection of Web server variables. |
| TotalBytes | Gets the number of bytes in the current input stream. |
| Url | Gets information about the URL of the current request. |
| UrlReferrer | Gets information about the URL of the client's previous request that is linked to the current URL. |
| UserAgent | Gets the raw user agent string of the client browser. |
| UserHostAddress | Gets the IP host address of the remote client. |
| UserHostName | Gets the DNS name of the remote client. |
| UserLanguages | Gets a sorted string array of client language preferences. |
下表列出了一些重要的方法：
| Method | Description |
|---|---|
| BinaryRead | Performs a binary read of a specified number of bytes from the current input stream. |
| Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from object.) |
| GetType | Gets the Type of the current instance. |
| MapImageCoordinates | Maps an incoming image-field form parameter to appropriate x-coordinate and y-coordinate values. |
| MapPath(String) | Maps the specified virtual path to a physical path. |
| SaveAs | Saves an HTTP request to disk. |
| ToString | Returns a String that represents the current object. |
| ValidateInput | Causes validation to occur for the collections accessed through the Cookies, Form, and QueryString properties. |
Response Object
Response對象表示伺服器對客戶端請求的響應。它是System.Web.HttpResponse類的一個實例。
在ASP.NET中，響應對象在向客戶端發送HTML文本方面沒有任何重要作用，因爲伺服器端控制項具有嵌套的、面向對象的方法來呈現它們自己。
然而，HttpResponse對象仍然提供一些重要的功能，比如cookie特性和Redirect（）方法。Response.Redirect（）方法允許將用戶轉移到應用程式內外的另一個頁面。它需要往返旅行。
Properties and Methods of the Response Object
下表提供了響應對象的一些值得注意的屬性：
| Property | Description |
|---|---|
| Buffer | Gets or sets a value indicating whether to buffer the output and send it after the complete response is finished processing. |
| BufferOutput | Gets or sets a value indicating whether to buffer the output and send it after the complete page is finished processing. |
| Charset | Gets or sets the HTTP character set of the output stream. |
| ContentEncoding | Gets or sets the HTTP character set of the output stream. |
| ContentType | Gets or sets the HTTP MIME type of the output stream. |
| Cookies | Gets the response cookie collection. |
| Expires | Gets or sets the number of minutes before a page cached on a browser expires. |
| ExpiresAbsolute | Gets or sets the absolute date and time at which to remove cached information from the cache. |
| HeaderEncoding | Gets or sets an encoding object that represents the encoding for the current header output stream. |
| Headers | Gets the collection of response headers. |
| IsClientConnected | Gets a value indicating whether the client is still connected to the server. |
| Output | Enables output of text to the outgoing HTTP response stream. |
| OutputStream | Enables binary output to the outgoing HTTP content body. |
| RedirectLocation | Gets or sets the value of the Http Location header. |
| Status | Sets the status line that is returned to the client. |
| StatusCode | Gets or sets the HTTP status code of the output returned to the client. |
| StatusDescription | Gets or sets the HTTP status string of the output returned to the client. |
| SubStatusCode | Gets or sets a value qualifying the status code of the response. |
| SuppressContent | Gets or sets a value indicating whether to send HTTP content to the client. |
下表列出了一些重要的方法：
| Method | Description |
|---|---|
| AddHeader | Adds an HTTP header to the output stream. AddHeader is provided for compatibility with earlier versions of ASP. |
| AppendCookie | Infrastructure adds an HTTP cookie to the intrinsic cookie collection. |
| AppendHeader | Adds an HTTP header to the output stream. |
| AppendToLog | Adds custom log information to the InterNET Information Services (IIS) log file. |
| BinaryWrite | Writes a string of binary characters to the HTTP output stream. |
| ClearContent | Clears all content output from the buffer stream. |
| Close | Closes the socket connection to a client. |
| End | Sends all currently buffered output to the client, stops execution of the page, and raises the EndRequest event. |
| Equals(Object) | Determines whether the specified object is equal to the current object. |
| Flush | Sends all currently buffered output to the client. |
| GetType | Gets the Type of the current instance. |
| Pics | Appends a HTTP PICS-Label header to the output stream. |
| Redirect(String) | Redirects a request to a new URL and specifies the new URL. |
| Redirect(String, Boolean) | Redirects a client to a new URL. Specifies the new URL and whether execution of the current page should terminate. |
| SetCookie | Updates an existing cookie in the cookie collection. |
| ToString | Returns a String that represents the current Object. |
| TransmitFile(String) | Writes the specified file directly to an HTTP response output stream, without buffering it in memory. |
| Write(Char) | Writes a character to an HTTP response output stream. |
| Write(Object) | Writes an object to an HTTP response stream. |
| Write(String) | Writes a string to an HTTP response output stream. |
| WriteFile(String) | Writes the contents of the specified file directly to an HTTP response output stream as a file block. |
| WriteFile(String, Boolean) | Writes the contents of the specified file directly to an HTTP response output stream as a memory block. |
Example
下面的簡單示例有一個文本框控制項，用戶可以在其中輸入名稱，一個按鈕將信息發送到伺服器，一個標籤控制項顯示客戶端計算機的URL。
內容文件：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs"
Inherits="server_side._Default" %>
<!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 runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
Enter your name:
<br />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Submit" />
<br />
<asp:Label ID="Label1" runat="server"/>
</div>
</form>
</body>
</html>
「代碼隱藏」按鈕單擊：
protected void Button1_Click(object sender, EventArgs e) {
if (!String.IsNullOrEmpty(TextBox1.Text)) {
// Access the HttpServerUtility methods through
// the intrinsic Server object.
Label1.Text = "Welcome, " + Server.HtmlEncode(TextBox1.Text) + ". <br/> The url is " + Server.UrlEncode(Request.Url.ToString())
}
}
運行該頁可查看以下結果：