Build Your Own ASP.NET 2.0 Web Site Using C# & VB, Second Edition

ASP.NET is all about controls, so we’ll be discussing them in greater detail as we

move through this book. In particular, Chapter 4 explains many of the controls

that ship with ASP.NET. For now, though, let’s continue with our dissection of

an ASP.NET page.

Server-side Comments

Server-side comments allow you to include within the page comments or notes

that will not be processed by ASP.NET. Traditional HTML uses the <!-- and -

-> character sequences to delimit comments; any information included between

these tags will not be displayed to the user. ASP.NET comments look very similar,

but use the sequences <%-- and --%>.

Our ASP.NET example contains the following server-side comment block:

File: Hello.aspx (excerpt)

<%-- Declare the title as string and set it --%>

The difference between ASP.NET comments and HTML comments is that

ASP.NET comments are not sent to the client at all; HTML comments are, so

they’re not suited to commenting out ASP.NET code. Consider the following

example:

C#

<!--

<% string Title = "This is generated by a code render block."; %>

<%= Title %>

-->

Here, it looks as if a developer has attempted to use an HTML comment to stop

a code render block from being executed. Unfortunately, HTML comments will

only hide information from the browser, not the ASP.NET runtime. So, in this

case, while we won’t see anything in the browser that represents these two lines,

they will be processed by ASP.NET, and the value of the variable Title will be

sent to the browser inside an HTML comment, as shown here:

<!–-

This code generated by a code render block.

-->

The code could be modified to use server-side comments very simply:

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Server-side Comments