广播的注册与注销

广播可以通过xml注册，或者直接代码注册

xml注册

      <intent-filter>
              <action android:name="android.intent.action.PACKAGE_ADDED" />
              <action android:name="android.intent.action.PACKAGE_REMOVED" />
              <data android:scheme="package"/>
      </intent-filter> 
</receiver>

代码注册

PackageReceiver packageReceiver = new PackageReceiver();
IntentFilter filter = new IntentFilter();
filter.addAction("android.intent.action.PACKAGE_ADDED");
filter.addAction("android.intent.action.PACKAGE_REMOVED");
filter.addDataScheme("package");
registerReceiver(packageReceiver, filter);

注销

unregisterReceiver(packageReceiver);