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CHAPTER 3: Activities
Caution The
priority attribute should be used with caution. A component cannot possibly
know what priorities other components from other apps can have. So, you introduce some kind of
dependency between apps, which is not intended by design.
This element can be a child of the following:
and
So, intents can be used to launch activities and services and to fire broadcast messages.
The element must contain children elements as follows:
(obligatory)
(optional)
(optional)
Intent Action
The child of the filter (or children, because you can have more than one) specifies
the action to perform. The syntax is as follows:
This will be something expressing an action such as View, Pick, Edit, Dial, and so on. The
complete list of generic actions is specified by constants with names like ACTION_* inside the
class android.content.Intent; you can find a list in the section “Intent Constituent Parts” in
the online text companion. Besides those generic actions, you can define your own actions.
Note Using any of the standard actions does not necessarily mean there is any app on your
device that is able to respond to a corresponding intent.
Intent Category
The child of the filter specifies a category for the filter. The syntax is as follows:
This attribute may be used to specify the type of component that an intent should address.
You can specify several categories, but the category is not used for all intents, and you can
omit it as well. The filter will match the intent only if all required categories are present.
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