GPS相关知识

public class Main extends Activity implements OnClickListener {
    private LocationManager locationManager;
    private Location location;
    private Criteria criteria;
    private String provider;

    private TextView tv_Latitude;// 纬度
    private TextView tv_Longitude;// 经度
    private TextView tv_High;// 海拔
    private TextView tv_Direction;// 方向
    private TextView tv_Speed;// 速度
    private TextView tv_GpsTime;// 获取的时间
    private TextView tv_InfoType;// 信息的来源
    private EditText et_SetTimeSpace;// 设置时间间隔

    private Button manual_btn;
    private Button settimespace_btn;
    private Button exit_btn;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setTitle("GPS");
        // 隐藏输入法
        getWindow().setSoftInputMode(
                WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
        initView();
        initLocation();
    }

    // 初始化
    @SuppressWarnings("static-access")
    private void initLocation() {
        // 初始化locationManager：获得系统所提供的location_service
        locationManager = (LocationManager) getSystemService(this.LOCATION_SERVICE);
        /**
         * LocationManager.GPS_PROVIDER
         * 
         * 精度比较高，但是慢而且消耗电力， 而且可能因为天气原因或者障碍物而无法获取卫星信息，另外设备可能没有GPS模块；
         * LocationManager.NETWORK_PROVIDER
         * 
         * 通过网络获取定位信息，精度低，耗电少，获取信息速度较快，不依赖GPS模块。
         */
        if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
            /* 注意：criteria有多种设置 */

            // 第一种：criteria
            criteria = new Criteria();
            criteria.setAccuracy(Criteria.ACCURACY_FINE);// 高精度
            criteria.setAltitudeRequired(true);// 显示海拔
            criteria.setBearingRequired(true);// 显示方向
            criteria.setSpeedRequired(true);// 显示速度
            criteria.setCostAllowed(false);// 不允许有花费
            criteria.setPowerRequirement(Criteria.POWER_LOW);// 低功耗

            // 第二种：criteria
            // criteria = new Criteria();
            // criteria.setAccuracy(Criteria.ACCURACY_FINE);//设置为最大精度
            // criteria.setAltitudeRequired(false);//不要求海拔信息
            // criteria.setBearingRequired(false);//不要求方位信息
            // criteria.setCostAllowed(true);//是否允许付费
            // criteria.setPowerRequirement(Criteria.POWER_LOW);//对电量的要求

            provider = locationManager.getBestProvider(criteria, true);

            locationManager.requestLocationUpdates(provider, 5000, 10,
                    locationListener);// 位置变化监听,默认5秒一次,距离10米以上
        } else
            showInfo(null, -1);
    }

    /**
     * 获取GPS相应的数据
     * 
     * @return
     */
    private GPSModel getLastPosition() {
        GPSModel gpsModel = new GPSModel();
        location = locationManager.getLastKnownLocation(provider);
        if (location != null) {
            gpsModel.Latitude = (double) (location.getLatitude());
            gpsModel.Longitude = (double) (location.getLongitude());
            gpsModel.High = location.getAltitude();
            gpsModel.Direct = location.getBearing();
            gpsModel.Speed = location.getSpeed();

            Date d = new Date();
            d.setTime(location.getTime());
            gpsModel.GpsTime = DateFormat.format("yyyy-MM-dd kk:mm:ss", d)
                    .toString();
            d = null;
        }
        return gpsModel;
    }

    // 显示信息
    private void showInfo(GPSModel gpsModel, int infotype) {
        if (gpsModel == null) {
            if (infotype == -1) {
                tv_Latitude.setText("GPS功能已关闭");
                tv_Longitude.setText("");
                tv_High.setText("");
                tv_Direction.setText("");
                tv_Speed.setText("");
                tv_GpsTime.setText("");
                tv_InfoType.setText("");
                manual_btn.setEnabled(false);
                settimespace_btn.setEnabled(false);
                et_SetTimeSpace.setEnabled(false);
            }
        } else {
            double y = gpsModel.Latitude;// 纬度
            double x = gpsModel.Longitude;// 经度
            tv_Latitude.setText("纬度：y=" + String.valueOf(y));
            tv_Longitude.setText("经度：x=" + String.valueOf(x));
            tv_High.setText(String.format("海拔:%f", gpsModel.High));
            tv_Direction.setText(String.format("方向:%f", gpsModel.Direct));
            tv_Speed.setText(String.format("速度:%f", gpsModel.Speed));
            tv_GpsTime.setText(String.format("GPS时间:%s", gpsModel.GpsTime));

            gpsModel.InfoType = infotype;
            switch (infotype) {
            case 1:
                tv_InfoType.setText("信息来源状态:手动获取更新");
                break;
            case 2:
                tv_InfoType.setText("信息来源状态:位置改变更新");
                break;
            }
        }

    }

    @SuppressWarnings("static-access")
    @Override
    public void onClick(View v) {
        if (v.equals(manual_btn)) {
            showInfo(getLastPosition(), 1);
        }
        if (v.equals(settimespace_btn)) {
            if (TextUtils.isEmpty(et_SetTimeSpace.getText().toString())) {
                Toast.makeText(this, "请输入更新时间间隔", Toast.LENGTH_LONG).show();
                et_SetTimeSpace.requestFocus();
                return;
            }

            int timespace = Integer.valueOf(et_SetTimeSpace.getText()
                    .toString()) * 1000;
            if (locationManager.isProviderEnabled(locationManager.GPS_PROVIDER))
                locationManager.requestLocationUpdates(provider, timespace, 10,
                        locationListener);
        }
        if (v.equals(exit_btn))
            android.os.Process.killProcess(android.os.Process.myPid());
    }

    private final LocationListener locationListener = new LocationListener() {

        @Override
        public void onLocationChanged(Location arg0) {
            showInfo(getLastPosition(), 2);
        }

        @Override
        public void onProviderDisabled(String arg0) {
            showInfo(null, -1);
        }

        @Override
        public void onProviderEnabled(String arg0) {
        }

        @Override
        public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
        }

    };

    private void initView() {
        tv_Latitude = (TextView) findViewById(R.id.tvlatitude);
        tv_Longitude = (TextView) findViewById(R.id.tvlongitude);
        tv_High = (TextView) findViewById(R.id.tvhigh);
        tv_Direction = (TextView) findViewById(R.id.tvdirection);
        tv_Speed = (TextView) findViewById(R.id.tvspeed);
        tv_GpsTime = (TextView) findViewById(R.id.tvgpstime);
        tv_InfoType = (TextView) findViewById(R.id.tvinfotype);
        et_SetTimeSpace = (EditText) findViewById(R.id.ettimespace);

        manual_btn = (Button) findViewById(R.id.btnmanual);
        manual_btn.setOnClickListener(this);
        settimespace_btn = (Button) findViewById(R.id.btnsettimespace);
        settimespace_btn.setOnClickListener(this);
        exit_btn = (Button) findViewById(R.id.btnexit);
        exit_btn.setOnClickListener(this);
    }

}