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
<) 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/index.html" to
"E:\Inetpub\wwwroot\myapp\index.html"). 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);
}
