注意：The <strong>categories</strong>, if supplied, must <em>all</em> be listed by the activity as categories it handles. That is, if you include the categories <code><a href="http://www.2233.cn/reference/android/content/Intent.html#CATEGORY_LAUNCHER">CATEGORY_LAUNCHER</a></code>and <code><a href="http://www.2233.cn/reference/android/content/Intent.html#CATEGORY_ALTERNATIVE">CATEGORY_ALTERNATIVE</a></code>, then you will only resolve to components with an intent that lists <em>both</em> of those categories. Activities will very often need to support the <code><a href="http://www.2233.cn/reference/android/content/Intent.html#CATEGORY_DEFAULT">CATEGORY_DEFAULT</a></code> so that they can be found by <code><a href="http://www.2233.cn/reference/android/content/Context.html#startActivity(android.content.Intent)">Context.startActivity()</a></code>.
调用自定义action实例：<a title="Intent_example.rar" href="http://www.2233.cn/class/wp-content/uploads/2013/07/Intent.rar">Intent</a>
调用系统action实例：<a href="http://www.2233.cn/class/wp-content/uploads/2013/07/DataAttr.rar">调用系统Action的Intent</a>
