GPS(2)关于位置的3个示例,实时获取GPS定位数据,求两个经纬点距离,邻近某个区域圆时警告

实时获取GPS定位数据

 import android.app.Activity;
 import android.content.Context;
 import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
 import android.os.Bundle;
 import android.widget.EditText;

 /*
  * 实时获取GPS定位数据
  */
 public class LocationActivity extends Activity
 {
     LocationManager mLocationManager;
     EditText mEditText;
     @Override
     public void onCreate(Bundle savedInstanceState)
     {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);

         mEditText = (EditText)findViewById(R.id.show);

         mLocationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

         //从 GPS_PROVIDER 获取最后已知的定位信息
         Location location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

         //在editview中显示该信息
         updateView(location);

         /*
          * 请求更新 location
          */
         //2000表示更新周期是2秒,8表示当新位置与当前位置超过8米时
         //2000与8米是或的关系.其中一个满足时就触发LocationListener回调
         mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, , , new LocationListener() {
             @Override
             public void onStatusChanged(String provider, int status, Bundle extras) {

             }
             @Override
             public void onProviderEnabled(String provider) {
                 //当PorviderLocation可用时的回调
                 updateView(mLocationManager.getLastKnownLocation(provider));
             }

             @Override
             public void onProviderDisabled(String provider) {
             }

             @Override
             public void onLocationChanged(Location location) {
                 //当gps位置信息变化时的回调
                 updateView(location);
             }
         });

     }    

     //在 EditView 中显示位置信息
     public void updateView(Location newLocation)
     {
         if(newLocation != null)
         {
             StringBuilder sb = new StringBuilder();

             sb.append("实时的位置信息:\n");

             sb.append("经度:" + newLocation.getLongitude() + "\n");
             sb.append("纬度:" + newLocation.getLatitude()  + "\n");
             sb.append("高度:" + newLocation.getAltitude()  + "\n");
             sb.append("速度:" + newLocation.getSpeed()     + "\n");
             sb.append("方向:" + newLocation.getBearing()   + "\n");

             mEditText.setText(sb.toString());
         }
     }
 }

求两个经纬点距离

 import android.app.Activity;
 import android.location.Location;
 import android.os.Bundle;
 import android.widget.EditText;

 /*
  * 求两个经纬点间距离
  */
 public class DistanceActivity extends Activity {
     private EditText mEditText;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_distance);

         mEditText = (EditText) findViewById(R.id.edittext);

         // 1,准备一个存放计算结果的数组,长度为3,最终距离为数组第1个元素的值,
         final float[] results = new float[];

         // 2,用Location.distanceBetween静态方法计算,前两个参数为第一个点的经纬度,第3,4个参数是第2个点的经纬度,
         Location.distanceBetween(20.123, 30.05644, 30.124, 40.543, results);
         mEditText.setText(String.valueOf(results[]) + "米");
     }
 }

邻近某个区域圆时警告

 import mobile.android.proximity.alert.R;
 import android.app.Activity;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.location.LocationManager;
 import android.os.Bundle;

 /*
  * 当进入目标区域时提示警告的示例
  * 目标区域是指 以某个经纬点为原点,半径为x的一个圆.
  */
 public class ProximityAlertActivity extends Activity{
     @Override
     public void onCreate(Bundle savedInstanceState){
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);    

         //进入目标区域提示警告 第1步,得到LocationManager
         LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

         //进入目标区域提示警告 第2步,准备目标区域
         double longitude = 123.427109;
         double latitude = 41.764998;
         float radius = ;//半径

         //进入目标区域提示警告 第3步,广播接收器的intent.PromimityAlertRecivery是个接收器.
         Intent intent = new Intent(this, PromimityAlertRecivery.class);

         //进入目标区域提示警告 第4步,将广播接收器与PendingIntent绑定.
         //PendingIntent 比intent生命周期长,应用关闭后,它仍然存在.除非卸载或关机.
         PendingIntent pendingIntent = PendingIntent.getBroadcast(this,,intent,);

         //进入目标区域提示警告 第5步,添加一个进入警告到LocationManager,其中-1这个参数是过期周期,-1表示永远
         locationManager.addProximityAlert(latitude, longitude, radius, -, pendingIntent);
     }
 }

接收器的代码

 import android.content.Context;
 import android.content.Intent;
 import android.location.LocationManager;
 import android.widget.Toast;

 /*
  * 注意这是个广播接收器,还是主动请求的数据的
  */
 public class PromimityAlertRecivery {

     public void onReceive(Context context, Intent intent) {
         //是否进入目标区域,true是进入,false是离开
         boolean isEnter = intent.getBooleanExtra(
                 LocationManager.KEY_PROXIMITY_ENTERING, false);

         if (isEnter) {
             Toast.makeText(context, "已经进入目标区域", Toast.LENGTH_LONG).show();
         } else {
             Toast.makeText(context, "已经离开目标区域", Toast.LENGTH_LONG).show();
         }

     }
 }