Question

// Rahees是Parse.com中用于android的类，我想从335位获取最近位置的列表.Rahees类的列名为“Locations”。

我希望通过将其与Rahees类的位置列中列出的地理位置进行比较来获取g中最近的地理位置列表

// ****************** Rahees班级************************ / /

@ParseClassName("Rahees")
public class Rahees extends ParseObject {

   public  Rahees()
    {
        super();
    }


    public String getDisplayName() {
        return getString("displayName");
    }
    public void setDisplayName(String value) {

        put("displayName", value);
    }
    public static ParseQuery<Rahees> getQuery() {
        return ParseQuery.getQuery(Rahees.class);
    }

}

// ************主要活动******************************* //

public class MainActivity extends AppCompatActivity {
    ParseGeoPoint g;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ParseUser cuser = ParseUser.getCurrentUser();

        Rahees haila = new Rahees();

        haila.setDisplayName("Rahim");

    }


   //button for Logging out of system
    public void logout(View view)
    {
        ParseUser.logOut();
        Intent intent = new Intent(MainActivity.this, SignUp_Login.class);
        startActivity(intent);


    }

//Button for going to Map Masti class, it is this button which triggers to compare the geopoint g with the geopoints in the server


    public void go_to_maps(View view)
    {

        Intent intent = new Intent(MainActivity.this, Map_Masti.class);
        startActivity(intent);
    }
}

// **************************** MapMasti班级*************** ************** //

public class Map_Masti extends FragmentActivity  {
    ParseGeoPoint g;
    private TextView textView;
    private SupportMapFragment mapFragment;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map_masti);

        textView = (TextView)findViewById(R.id.text);
        mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map_fragment);

//Query to get the geopoint g from server 

        ParseQuery<ParseUser> query = ParseUser.getQuery();
        query.getInBackground("ccm3xKMmr4", new GetCallback<ParseUser>() {
            public void done(ParseUser object, ParseException e) {
                if (e == null) {
                    g = (ParseGeoPoint) object.get("user_Location");
                    Log.d("mohit", g + "");

                } else {
                    // something went wrong
                    Log.d("mohit", e + " ");
                }
            }
        });

//查询比较对象“Rahees”中哪些地理位置与“Locations”列接近地理位置“g”

 ParseQuery<Rahees> mapQuery1 = Rahees.getQuery();
        mapQuery1.whereWithinKilometers("Locations", g, 6000);
        mapQuery1.setLimit(3);
        mapQuery1.findInBackground(new FindCallback<Rahees>() {
            @Override
            public void done(List<Rahees> objects, ParseException e) {
                // Handle the results
                if (e == null) {//****this is where the exception error comes, it doesn't goes inside if statement**** 
                    for (int i = 0; i < objects.size(); i++) {
                        Log.d("mohit", "2" + objects.get(i).get("Locations"));

                    }
                } else {
                    Log.d("mohit", "" + e);
                }
            }
        });

}
}

以下是我从其他部分

获得的错误

01-10 12：27：38.655 4348-4348 /？ D /错误：com.parse.ParseRequest $ ParseRequestException：$ nearSphere需要一个map运算符

我可以从Parse中检索g的值，log的输出为g是： ParseGeoPoint [40.000000,30.000000]

请帮忙

Answer 1

您应该在获得第一个查询后才进行第二次查询，因为g为null，直到将通过回调进行初始化。

更新

public class Map_Masti extends FragmentActivity {
    ParseGeoPoint g;
    private SupportMapFragment mapFragment;
    private TextView textView;

    private void getG() {
        ParseQuery<ParseUser> query = ParseUser.getQuery();
        query.getInBackground("ccm3xKMmr4", new GetCallback<ParseUser>() {
            public void done(ParseUser object, ParseException e) {
                if (e == null) {
                    g = (ParseGeoPoint) object.get("user_Location");
                    Log.d("mohit", g + "");
                    getLocations();

                } else {
                    // something went wrong
                    Log.d("mohit", e + " ");
                }
            }
        });
    }

    private void getLocations() {
        ParseQuery<Rahees> mapQuery1 = Rahees.getQuery();
        mapQuery1.whereWithinKilometers("Locations", g, 6000);
        mapQuery1.setLimit(3);
        mapQuery1.findInBackground(new FindCallback<Rahees>() {
            @Override
            public void done(List<Rahees> objects, ParseException e) {
                // Handle the results
                if (e == null) {//****this is where the exception error comes, it doesn't goes inside if statement****
                    for (int i = 0; i < objects.size(); i++) {
                        Log.d("mohit", "2" + objects.get(i).get("Locations"));

                    }
                } else {
                    Log.d("mohit", "" + e);
                }
            }
        });
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.map_masti);
        textView = (TextView) findViewById(R.id.text);
        mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map_fragment);
        getG();
    }
}

nearSphere需要一个map运算符

1 个答案: