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Android implementation of GPS positioning code example

高洛峰
高洛峰Original
2017-01-07 14:55:572067browse

What is obtained through GPS is a Location type latitude and longitude, which can be converted into two Double latitude and longitude.
Latitude: 23.223871812820435
Latitude: 113.58986039161628
First create a TextView and two Buttons


  
 

Then add the code of the main Activity
Location is a type that stores longitude and latitude
LocationManager is the location management service type

private Button btnStart;
private Button btnStop;
private TextView textView;
private Location mLocation;
private LocationManager mLocationManager;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
  
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
  
 btnStart = (Button)findViewById(R.id.btnStart);
 btnStop = (Button)findViewById(R.id.btnStop);
 textView = (TextView)findViewById(R.id.text);
 btnStart.setOnClickListener(btnClickListener); //开始定位
 btnStop.setOnClickListener(btnClickListener); //结束定位按钮
}
gpsIsOpen是自己写的查看当前GPS是否开启
getLocation 是自己写的一个获取定位信息的方法
mLocationManager.removeUpdates()是停止当前的GPS位置监听
public Button.OnClickListener btnClickListener = new Button.OnClickListener()
{
 public void onClick(View v)
 {
  Button btn = (Button)v;
  if(btn.getId() == R.id.btnStart)
  {
   if(!gpsIsOpen())
    return;
    
  mLocation = getLocation();
    
   if(mLocation != null)
    textView.setText("维度:" + mLocation.getLatitude() + "\n经度:" + mLocation.getLongitude());
   else
    textView.setText("获取不到数据");
  }
  else if(btn.getId() == R.id.btnStop)
  {
   mLocationManager.removeUpdates(locationListener);
  }
 
 }
};
private boolean gpsIsOpen()
{
 boolean bRet = true;
 
 LocationManager alm = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
 if(!alm.isProviderEnabled(LocationManager.GPS_PROVIDER))
 {
  Toast.makeText(this, "未开启GPS", Toast.LENGTH_SHORT).show();
  bRet = false;
 }
 else
 {
  Toast.makeText(this, "GPS已开启", Toast.LENGTH_SHORT).show();
 }
 
 return bRet;
}
判断当前是否开启GPS
private boolean gpsIsOpen()
{
 boolean bRet = true;
  
 LocationManager alm = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
 if(!alm.isProviderEnabled(LocationManager.GPS_PROVIDER))
 {
  Toast.makeText(this, "未开启GPS", Toast.LENGTH_SHORT).show();
  bRet = false;
 }
 else
 {
  Toast.makeText(this, "GPS已开启", Toast.LENGTH_SHORT).show();
 }
 
 return bRet;
}
该方法获取当前的经纬度, 第一次获取总是null
后面从LocationListener获取已改变的位置
mLocationManager.requestLocationUpdates()是开启一个LocationListener等待位置变化
private Location getLocation()
{
 //获取位置管理服务
 mLocationManager = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
 
 //查找服务信息
 Criteria criteria = new Criteria();
 criteria.setAccuracy(Criteria.ACCURACY_FINE); //定位精度: 最高
 criteria.setAltitudeRequired(false); //海拔信息:不需要
 criteria.setBearingRequired(false); //方位信息: 不需要
 criteria.setCostAllowed(true);  //是否允许付费
 criteria.setPowerRequirement(Criteria.POWER_LOW); //耗电量: 低功耗
  
 String provider = mLocationManager.getBestProvider(criteria, true); //获取GPS信息
 
 Location location = mLocationManager.getLastKnownLocation(provider);
  
 mLocationManager.requestLocationUpdates(provider, 2000, 5, locationListener);
  
 return location;
}
改方法是等待GPS位置改变后得到新的经纬度
private final LocationListener locationListener = new LocationListener()
{
 public void onLocationChanged(Location location)
 {
  // TODO Auto-generated method stub
  if(location != null)
   textView.setText("维度:" + location.getLatitude() + "\n经度:"
      + location.getLongitude());
  else
   textView.setText("获取不到数据" + Integer.toString(nCount));
 }
 
 public void onProviderDisabled(String provider)
 {
  // TODO Auto-generated method stub
 }
 
 public void onProviderEnabled(String provider)
 {
  // TODO Auto-generated method stub
 }
 
 public void onStatusChanged(String provider, int status, Bundle extras)
 {
  // TODO Auto-generated method stub
   
 }
};


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