Telephony_service for systemservice Learning

Telephonymanager mtelephonymgr = (telephonymanager) getsystemservice (context. telephony_service );

Telephonymanager provides a method for obtaining mobile phone information, including call status, network connection, and carrier information,

The following example shows how telephonymanager monitors the call status:

import android.os.Bundle;import android.app.Activity;import android.content.BroadcastReceiver;import android.content.Context;  import android.content.IntentFilter;import android.telephony.PhoneStateListener;  import android.telephony.TelephonyManager;  import android.util.Log;  import android.widget.TextView;  public class MainActivity extends Activity {  private static final String TAG = "Telephony";  TextView view = null;  @Override  protected void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      TelephonyManager mTelephonyMgr =         (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);      mTelephonyMgr.listen(new TeleListener(),PhoneStateListener.LISTEN_CALL_STATE);      view = new TextView(this);      view.setText("listen the state of phone\n");      setContentView(view);  }      class TeleListener extends PhoneStateListener {       @Override        public void onCallStateChanged(int state, String incomingNumber)        {            super.onCallStateChanged(state, incomingNumber);            switch (state) {                case TelephonyManager.CALL_STATE_IDLE: {                   Log.d(TAG, "CALL_STATE_IDLE");                   view.append("CALL_STATE_IDLE " + "\n");                   break;                  }              case TelephonyManager.CALL_STATE_OFFHOOK: {                   Log.d(TAG, "CALL_STATE_OFFHOOK");                   view.append("CALL_STATE_OFFHOOK" + "\n");                   break;                  }             case TelephonyManager.CALL_STATE_RINGING: {                     Log.d(TAG, "CALL_STATE_RINGING");                     view.append("CALL_STATE_RINGING" + "\n");                  break;                  }          default:          Log.d(TAG, " the statu is"+state);        break;            }          }     }  }