ASP.NET.in.a.Nutshell.Second.Edition [Electronic resources]

G. andrew Duthie; matthew Macdonald

نسخه متنی -صفحه : 873/ 165
نمايش فراداده

HttpServerUtility

System.Web (system.web.dll)sealed class

This class provides helper methods and is available through the built-in Server object. It provides the useful UrlEncode( ) method, which converts a string into a form suitable for use as a query string variable, and the HtmlEncode( ) method, which converts nonlegal HTML characters in a string into the equivalent HTML entity (i.e., "<" is converted to &lt;) so they can be displayed on a page. Some ASP.NET web controls (like buttons) do not require this conversion, but label controls do. You may need to use the HtmlEncode( ) method manually if you bind a field with URL information from a database. It also always a good idea to use HtmlEncode( ) before displaying user-supplied content to prevent possible script injection attacks.

The HttpServerUtility class provides the MapPath( ) method, which takes a string representing a virtual path and returns the real (physical) path (for example, it could convert "/myapp/indexl" to "E:\Inetpub\wwwroot\myapp\indexl"). It also provides a CreateObject( ) method for instantiating a COM object by using its ProgID (i.e., objInfo=Server.CreateObject ("MSWC.MyInfo");) and the two flow control methods Execute( ) and Transfer( ). The Execute( ) method, which runs the script in a separate ASP.NET page and then returns control to the current page, is rarely used in class-based ASP.NET programming. The Transfer( ) method halts the execution of the current page and transfers execution to the specified page. It is similar to the HttpResponse.Redirect( ) method, but does not require a roundtrip to the client and back and cannot transfer execution to a page on another server (or from an ASP.NET page to an ASP page).

public sealed class 

HttpServerUtility { // Public Instance Properties public string

MachineName {get; } public int

ScriptTimeout {set; get; } // Public Instance Methods public void

ClearError ( ); public object

CreateObject (string

progID ); public object

CreateObject (Type

type ); public object

CreateObjectFromClsid (string

clsid ); public void

Execute (string

path ); public void

Execute (string

path , System.IO.TextWriter

writer ); public Exception

GetLastError ( ); public string

HtmlDecode (string

s ); public void

HtmlDecode (string

s , System.IO.TextWriter

output ); public string

HtmlEncode (string

s ); public void

HtmlEncode (string

s , System.IO.TextWriter

output ); public string

MapPath (string

path ); public void

Transfer (string

path ); public void

Transfer (string

path , bool

preserveForm ); public string

UrlDecode (string

s ); public void

UrlDecode (string

s , System.IO.TextWriter

output ); public string

UrlEncode (string

s ); public void

UrlEncode (string

s , System.IO.TextWriter

output ); public string

UrlPathEncode (string

s ); }

Returned By

HttpApplication.Server, HttpContext.Server, System.Web.Services.WebService.Server, System.Web.UI.Page.Server, System.Web.UI.UserControl.Server