Intent探索

intent的分类

Intent分为两种，显式intent和隐式intent，显式intent直接指明了接收的Activity，隐式intent没有直接指出接收的Activity，而是需要去AndroidManifest.xml文件中去匹配。Activity匹配隐式intent的条件有三个，Action，Category，Data这三个条件均位于intent-filter标签。Android本身库中提供了标准的Action和Category库，定义了data的格式。

intent的官方描述

An intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an Activity, broadcastIntent to send it to any interested BroadcastReceiver components, and startService(Intent) or bindService(Intent, ServiceConnection, int) to communicate with a background Service.

An Intent provides a facility for performing late runtime binding between the code in different applications. Its most significant use is in the launching of activities, where it can be thought of as the glue between activities. It is basically a passive data structure holding an abstract description of an action to be performed.

常用的函数

构造函数

高频函数

intent-filter实例

<intent-filter>     <action android:name="android.intent.action.VIEW" />     <action android:name="android.intent.action.EDIT" />     <action android:name="android.intent.action.PICK" />     <category android:name="android.intent.category.DEFAULT" />     <data android:mimeType="vnd.android.cursor.dir/vnd.google.note" /> </intent-filter>

注意事项：
1. 隐式intent查询时的优先级为action->data->category
2. action的值就是一个字符串，可以随意设置，只要匹配就可以