Android实现GPS定位代码实例

通过GPS取得的是一个Location类型的经纬度， 可以转换为两个Double 纬度和经度.
纬度: 23.223871812820435
纬度: 113.58986039161628
首先创建一个TextView和两个Button

<TextView
android:id="@+id/text"
android:layout_width="fill_parent"
 android:layout_height="wrap_content"  />

<Button
 android:id="@+id/btnStart"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="定位" />
<Button
 android:id="@+id/btnStop"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="停止" />

然后添加主Activity的代码
Location 是存放经纬度的一个类型
LocationManager是位置管理服务类型

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

}
};