Android服务监控

我只贴了关键代码，其实就是import android.telephony.ServiceState

ServiceState ss=new ServiceState();
                int s;
                s=ss.getState();
                switch(s)
                {
                case ServiceState.STATE_EMERGENCY_ONLY:
                	Toast toast1=Toast.makeText(GSMDetector.this,"Emegency_only", Toast.LENGTH_SHORT);
                	toast1.show();
                	break;
                case ServiceState.STATE_IN_SERVICE:
                	Toast toast2=Toast.makeText(GSMDetector.this,"in_Service", Toast.LENGTH_SHORT);
                	toast2.show();
                	break;
                case ServiceState.STATE_OUT_OF_SERVICE:
                	Toast toast3=Toast.makeText(GSMDetector.this,"out_of_Service", Toast.LENGTH_SHORT);
                	toast3.show();
                	break;
                case ServiceState.STATE_POWER_OFF:
                	Toast toast4=Toast.makeText(GSMDetector.this,"Power_off", Toast.LENGTH_SHORT);
                	toast4.show();
                	break;