The Structure of an ASP.NET Page

The following is a list of the important elements of an ASP.NET page:

1. Directives

2. Code declaration blocks

3. ASP.NET controls

4. Code render blocks

5. Server-side comments

6. Server-side include directives

7. Literal text and HTML tags

1. Directives

A directive controls how an ASP.NET page is compiled. The beginning of a directive is marked with the characters <%@

and the end of a directive is marked with the characters %>. A directive can appear anywhere within a page. By convention,

however, a directive typically appears at the top of an ASP.NET page.

There are several types of directives that you can add to an ASP.NET page. Two of the most useful types are page and import

directives.

Page Directives

You can use a page directive to specify the default programming language for a page.

<%@ Page Language="VB" %>

Import Directives

By default, only certain namespaces are automatically imported into an ASP.NET page. If you want to refer to a class that

isn't a member of one of the default namespaces, then you must explicitly import the namespace of the class.

<%@ Import Namespace="System.Web.Mail" %>

2. Code Declaration Blocks

A code declaration block contains all the application logic for your ASP.NET page and all the global variable declarations,

subroutines, and functions. It must appear within a

3. ASP.NET Controls

ASP.NET controls can be freely placed with the text and HTML content of a page. The only requirement is that the controls

should appear within a

tag.

One significant limitation of ASP.NET pages is that they can contain only one tag. This

means that you cannot group ASP.NET into multiple forms on a page. If you try, you get an error.

4. Code Render Blocks

If you need to execute code within the HTML or text content of your ASP.NET page, you can do so within code render

blocks. The two types of code render blocks are inline code and inline expressions. Inline code executes a statement or series

of statements. This type of code begins with the characters <% and ends with the characters %>.

Inline expressions, on the other hand, display the value of a variable or method (this type of code is shorthand for

Response.Write). Inline expressions begin with the characters <%= and end with the characters %>.

Inline expressions, on the other hand, display the value of a variable or method (this type of code is shorthand for

Response.Write). Inline expressions begin with the characters <%= and end with the characters %>.

5. Server-side Comments

You can add comments to your ASP.NET pages by using server-side comment blocks. The beginning of a server-side

comment is marked with the characters <%-- and the end of the comment is marked with the characters --%>.

6. Server-side Include Directives

You can include a file in an ASP.NET page by using one of the two forms of the server-side include directive. If you want

to include a file that is located in the same directory or in a subdirectory of the page including the file, you would use the

following directive:

7. Literal Text and HTML Tags

The final type of element that you can include in an ASP.NET page is HTML content. The static portion of your page is built

with plain old HTML tags and text.