Android Tutorial - Android Basic syntax for create resource ID

When you write

<TextView android:id="@+id/text1" ..../>

Its meaning is, "Use text1 to reference this instanceof TextView."

The + indicates that if the id of text1 is not defined as a resource, go ahead and define it with a unique number.

Define Your Own Resource IDs

It is possible to create IDs and use them in your own application.

IDs are treated as resources.

We can use a resource tag called item to define an ID without attaching to any particular resource as the following example.

   <item type="id" name="text"/>

The type refers to the type of resource id in this case. Once this ID is in place, the View definition in the following will work.

<TextView android:id="@id/text">