一些小技巧(持续更新……)

监听网络状态的改变 ： 
权限 ： <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>

public class MyBroastCast extends BroadcastReceiver {

	private static final String ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
	
	@Override
	public void onReceive(Context context, Intent intent) {
		if (intent.getAction().equals(ACTION)){
		Intent i= new Intent(context, XXXService.class);
		context.startService(i);
		}
	}
}
XXXService为你的Service

AndroidManifest.xml中添加：
<receiver android:name=".MyBroastCast">
	    <intent-filter>
	        <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
	    </intent-filter>
	</receiver> 

 横竖屏切换时，Dialog不会消失的配置：
 <activity>android:configChanges="navigation|orientation|keyboardHidden"