Immediate Solutions: Using the System.Web.UI.Page Class

Any Web page requested from a server hosting the .NET framework, whether it contains .NET code or only HTML text, is actually based on the System.Web.UI.Page class; this is the class that our Web forms inherit from:

Public Class WebForm1
    Inherits System.Web.UI.Page
       ⋮

Here is the class hierarchy for the Page class (note that the Control class here is the ASP .NET Control class, not the Windows application's Control class):

Object
   Control
      TemplateControl
         Page

You can find the notable public properties of Page objects in Table 14.5, the notable methods in Table 14.6, and the notable events in Table 14.7. Note that I'm not including all the properties, methods, and events that the Page class inherits from the System.Web.UI.Control class—you can find them in Chapter 15, Tables 15.1, 15.2, and Tables 15.3. (The Page class doesn't inherit members from the TemplateControl class that you normally deal with directly.)

Table 14.5: Noteworthy public properties of *Page* objects.
Property	Means
Application	Gets an Application object.
ClientTarget	Gets/sets if you want to override automatic browser capabilities detection and handle page rendering for specific browsers.
ErrorPage	Gets/sets an error page's URL in case there are unhandled page exceptions.
IsPostBack	Indicates if a page was created after a client postback, or if it is being loaded for the first time.
IsValid	Indicates if a page validation was successful.
Request	Gets the current HTTP Request object.
Response	Gets the current HTTP Response object.
Server	Gets the current Server object.
Session	Gets the current Session object.
Site	Gets Web site data.
User	Gets data about the user.
Validators	Gets a collection of the validation controls in the page.

Table 14.6: Noteworthy public methods of *Page* objects.
Method	Means
HasControls	Indicates if the form has any child controls.
LoadControl	Gets a UserControl object.
MapPath	Connects a virtual path to an actual path.
ResolveUrl	Converts a relative URL to an absolute URL.
Validate	Validates data using validation control in the page.

Table 14.7: Noteworthy public events of *Page* objects.
Event	Means
Disposed	Occurs when a Web form is disposed.
Error	Occurs when an unhandled exception has occurred.
Init	Occurs when the Web form is initialized.
Load	Occurs when the Web form is loaded.
Unload	Occurs when the server control is unloaded.