Question

我想通过从SQLite中检索经度和纬度来显示用户在谷歌地图上的GPS位置。请告诉我在Google地图上显示来自SQLite的信息的程序。这是我用来保存经度和纬度的代码。我也在使用这个链接 http://www.androidhive.info/2012/01/android-working-with-google-maps/ 对于地图，但不知道如何从SQLite中检索经度和纬度。 MAiN ACTIVITY：

  public class MainActivity extends Activity {

      ListView list;
      mylocation loc = new mylocation();
      @Override
      protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      LocationManager mylocman = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
      LocationListener myloclist = new mylocation();
      mylocman.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,myloclist);

     loc.updateDatabase(this);



     GPSdatabase myDatabase=new GPSdatabase(this);
     myDatabase.open(); 
     Cursor cursor=myDatabase.getAllRows(); 
     cursor.moveToFirst(); 
     ArrayList listContents = new ArrayList(); 
     for (int i = 0; i < cursor.getCount(); i++) 
     { 
         listContents.add("Lat=" +cursor.getString(1) +" "+"Log "+ cursor.getString(2)); 
         cursor.moveToNext(); } myDatabase.close(); 
         ListAdapter adapter=new ArrayAdapter(this,android.R.layout.simple_dropdown_item_1line,                          listContents); 
         list=(ListView)findViewById(R.id.list); 
         list.setAdapter(adapter);
}


    /*public void updateDatabase(){
    GPSDatabase myDatabase=new GPSDatabase(context);
    myDatabase.open();
    myDatabase.insertRow(lat.substring(0,4),log.substring(0,4));
    myDatabase.close();
            }*/



      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
   }

      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

}

我的位置calss：

public class mylocation implements LocationListener {
    String lat=null;
    String log=null;
    @Override
    public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub
    String text="my latitude="+location.getLatitude()+"longitude="+location.getLongitude();
     lat=location.getLatitude()+"";
     log=location.getLongitude()+"";
    //updateDatabase();

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

    }

    @Override
    public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub

    }

    @Override
    public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub

    }
    public void updateDatabase(Context context)
    {
    if(lat!=null || log!=null)
    {   
        GPSdatabase myDatabase=new GPSdatabase(context);
        myDatabase.open();
        myDatabase.insertRows(lat.substring(0,4),log.substring(0,4));
        myDatabase.close();
    }
    }


    }

我的数据库类：

公共类GPS数据库{

            private Context context;

            private DbHelper dbHelper;

            public final String DBNAME="gps1";

            public final int DBVERSION=3;

            public SQLiteDatabase db;

            public final String COLUMN2="latitude";

            public final String COLUMN3="longitude";

            public final String COLUMN1="locationId";

            public final String TABLENAME="location";

            public final String CREATERDB="create table location(locationId integer primary key autoincrement, latitude text not null, longitude text not null);";




            public GPSdatabase(Context context){

            this.context=context;

            dbHelper=new DbHelper(context);

            }

            public class DbHelper extends SQLiteOpenHelper{

            public DbHelper(Context context){

           super(context,DBNAME,null,DBVERSION);

              }

                @Override

                public void onCreate(SQLiteDatabase db) {

                    // TODO Auto-generated method stub

                    String CREATE_TABLE = "CREATE TABLE " + "location" + "("
                            + "latitude" + " TEXT,"
                            + "longitude" + " TEXT)";
                    db.execSQL(CREATE_TABLE);

                }

                @Override

                public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {


                }
            }

              public long insertRows(String column2, String column3){

              ContentValues value=new ContentValues();

              value.put(COLUMN2, column2);

             value.put(COLUMN3, column3);
             return db.insert(TABLENAME,null,value);

            }

            public Cursor getAllRows(){

            Cursor cursor=db.query(TABLENAME, new String[]{COLUMN1,COLUMN2,COLUMN3},     null,null, null, null, null);

            return cursor;

            }

          public void open() throws  SQLException{

              db =        dbHelper.getWritableDatabase();

                //return true;

            }

          public void close(){

                dbHelper.close();

                //return true;


        }}

Answer 1

为什么不直接显示用户的位置而不保存和来回检索？如果您告诉地图显示用户位置，则会自动完成： http://developer.android.com/reference/com/google/android/gms/maps/GoogleMap.html#setMyLocationEnabled(boolean)

map.setMyLocationEnabled(true);

在谷歌地图上显示GPS位置

1 个答案: