Visual Studio Hacks

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Chapter 4, Customizing Visual Studio

#32 Enable IntelliSense for HTML and XML Documents

HACK

Considerations for Custom Controls

Creating schema for a custom control often involves extending the existing

schema of one of ASP.NET’s built-in controls. In this situation, we can elim-

inate a lot of typing and create a more useful schema by copying the appro-

priate portions of the default ASP.NET schema. After creating your schema

file, locate and open the file <VS Install Directory>\Common7\Packages\

schemas\xml\asp.xsd. This file contains the schema for all the built-in con-

trols. Find and copy into your new schema the appropriate

attributeGroup

elements that apply to your control.

Editing the asp.xsd is a bad idea. Not only are you poten-

tially breaking IntelliSense for the built-in controls, but the

next time you upgrade or patch Visual Studio, your changes

will probably be lost.

In most cases, you will be able to use the ControlAttributes group even if no

other groups apply. After pasting these definitions into your schema, you

can simply reference them with an attribute group tag inside the appropri-

ate type:

<xsd:attributeGroup ref="ControlAttributes" />

After that, your type will automatically provide all the attributes defined in

the referenced attribute group.

Installing the Schema

After you have created the schema, you need to place it where Visual Studio

expects to find it. The normal