android GPS 获取卫星数量

 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;

 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.location.GpsSatellite;
 import android.location.GpsStatus;
 import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
 import android.os.Bundle;
 import android.provider.Settings;
 import android.view.KeyEvent;
 import android.view.View;
 import android.widget.Button;
 import android.widget.TextView;
 import android.widget.Toast;

 /**
  * @author liuzhidong
  * @create date 2012-08
  * @modifydate 2012.09.24
  */
 public class GPSActivity extends Activity {

     private TextView tv_gps, tv_satellites;
     private Button bt_Quit;
     LocationManager locationManager;
     private StringBuilder sb;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_gps);

         tv_satellites = (TextView)this.findViewById(R.id.tv_satellites);
         tv_gps = (TextView) this.findViewById(R.id.tv_gps);
         bt_Quit = (Button) this.findViewById(R.id.bt_quit_gps);

         openGPSSettings();

         LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
         String provider = LocationManager.GPS_PROVIDER;
         Location location = locationManager.getLastKnownLocation(provider);
         updateMsg(location);

         LocationListener ll = new LocationListener() {

             @Override
             public void onLocationChanged(Location location) {
                 String locInfo = updateMsg(location);
                 tv_gps.setText(null);
                 tv_gps.setText(locInfo);
             }

             @Override
             public void onStatusChanged(String provider, int status,
                     Bundle extras) {

             }

             @Override
             public void onProviderEnabled(String provider) {

             }

             @Override
             public void onProviderDisabled(String provider) {

             }

         };

         locationManager.requestLocationUpdates(provider, 1000, 1, ll);

         bt_Quit.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 GPSActivity.this.finish();
             }
         });

         locationManager.addGpsStatusListener(statusListener);
     }

     private String updateMsg(Location loc) {
         sb = null;
         sb = new StringBuilder("位置信息：\n");
         if (loc != null) {
             double lat = loc.getLatitude();
             double lng = loc.getLongitude();

             sb.append("纬度：" + lat + "\n经度：" + lng);

             if (loc.hasAccuracy()) {
                 sb.append("\n精度：" + loc.getAccuracy());
             }

             if (loc.hasAltitude()) {
                 sb.append("\n海拔：" + loc.getAltitude() + "m");
             }

             if (loc.hasBearing()) {// 偏离正北方向的角度
                 sb.append("\n方向：" + loc.getBearing());
             }

             if (loc.hasSpeed()) {
                 if (loc.getSpeed() * 3.6 < 5) {
                     sb.append("\n速度：0.0km/h");
                 } else {
                     sb.append("\n速度：" + loc.getSpeed() * 3.6 + "km/h");
                 }

             }
         } else {
             sb.append("没有位置信息！");
         }

         return sb.toString();
     }

     private void openGPSSettings() {
         LocationManager alm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
         if (alm.isProviderEnabled(android.location.LocationManager.GPS_PROVIDER)) {
             Toast.makeText(this, "GPS模块正常", Toast.LENGTH_SHORT).show();
             return;
         }

         Toast.makeText(this, "请开启GPS！", Toast.LENGTH_SHORT).show();
         Intent intent = new Intent(Settings.ACTION_SECURITY_SETTINGS);
         startActivityForResult(intent, 0); // 此为设置完成后返回到获取界面
     }

     public boolean onKeyDown(int keyCode, KeyEvent event) {
         if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
             GPSActivity.this.finish();
         }
         return super.onKeyDown(keyCode, event);
     }

     /**
      * 卫星状态监听器
      */
     private List<GpsSatellite> numSatelliteList = new ArrayList<GpsSatellite>(); // 卫星信号

     private final GpsStatus.Listener statusListener = new GpsStatus.Listener() {
         public void onGpsStatusChanged(int event) { // GPS状态变化时的回调，如卫星数
             LocationManager locationManager = (LocationManager) GPSActivity.this.getSystemService(Context.LOCATION_SERVICE);
             GpsStatus status = locationManager.getGpsStatus(null); //取当前状态
             String satelliteInfo = updateGpsStatus(event, status);
             tv_satellites.setText(null);
             tv_satellites.setText(satelliteInfo);
         }
     };

     private String updateGpsStatus(int event, GpsStatus status) {
         StringBuilder sb2 = new StringBuilder("");
         if (status == null) {
             sb2.append("搜索到卫星个数：" +0);
         } else if (event == GpsStatus.GPS_EVENT_SATELLITE_STATUS) {
             int maxSatellites = status.getMaxSatellites();
             Iterator<GpsSatellite> it = status.getSatellites().iterator();
             numSatelliteList.clear();
             int count = 0;
             while (it.hasNext() && count <= maxSatellites) {
                 GpsSatellite s = it.next();
                 numSatelliteList.add(s);
                 count++;
             }
             sb2.append("搜索到卫星个数：" + numSatelliteList.size());
         }

         return sb2.toString();
     }
 }