implicit intent 打开Activity 注意点

[chufengma]

一般都是设置

<activity>
 <action android:name="com.example.demo.XXXX"  />  
</activity>

其它Application中的Activity 调用 startActivity：

Intent intent = new Intent("com.example.demo.XXXX");
startActivity(intent);

这个时候直接启动会失败，往往我们忘记在activity intent-filter中添加:

<activity>
 <action android:name="com.example.demo.XXXX"  />  
 <category android:name="android.intent.category.LAUNCHER" />
</activity>

In order to receive implicit intents, you must include the CATEGORY_DEFAULT category in the intent filter. The methods startActivity() and startActivityForResult() treat all intents as if they declared the CATEGORY_DEFAULT category. If you do not declare it in your intent filter, no implicit intents will resolve to your activity.