如何修改 onMapReady 函数以从 json 标记地图

Question

我在使用 google map android 时遇到问题，我想从 json 中显示我的坐标。 我的 Json ：

{"info":[{"nama":"Masjid Agung","0":"Masjid Agung","deskripsi":"tempat sholat umat Isalm","1":"tempat sholat umat Isalm","lng":"106.332725524902","2":"106.332725524902","lat":"-6.23728179931641","3":"-6.23728179931641"},{"nama":"Restoran Bersama","0":"Restoran Bersama","deskripsi":"temapt makan","1":"temapt makan","lng":"106.309807206177","2":"106.309807206177","lat":"-6.23967002769392","3":"-6.23967002769392"},{"nama":"Restoran Cepat saja","0":"Restoran Cepat saja","deskripsi":"enak nih di sini","1":"enak nih di sini","lng":"106.318476105713","2":"106.318476105713","lat":"-6.22431180265454","3":"-6.22431180265454"},{"nama":"Bandara Halim","0":"Bandara Halim","deskripsi":"benarkah tidak ini bandara","1":"benarkah tidak ini bandara","lng":"106.34568443396","2":"106.34568443396","lat":"-6.24939667082029","3":"-6.24939667082029"},{"nama":"Bandara ABC","0":"Bandara ABC","deskripsi":"Ini adalah bandara","1":"Ini adalah bandara","lng":"106.331951523804","2":"106.331951523804","lat":"-6.22013087470731","3":"-6.22013087470731"}]}

这是我的 MainActivity：

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        LatLng sydney = new LatLng(-34, 151);
        mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
    }
}

任何人都可以帮助我如何自定义 onMapReady 函数以显示来自 json 的坐标。

谢谢

Answer 1

这是工作代码：

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    LatLng sydney = new LatLng(-34, 151);
    mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));

    // Fetch data
    fetchDataFromJSON();
}

private void fetchDataFromJSON()
{
    // JSON response
    String strResponse = "{\"info\":[{\"nama\":\"Masjid Agung\",\"0\":\"Masjid Agung\",\"deskripsi\":\"......";

    try
    {
        JSONObject response = new JSONObject(strResponse);
        JSONArray jsonArray = response.getJSONArray("info");

        // Clear old markers
        mMap.clear();

        // Looping through all info and show on map
        for (int i = 0; i < jsonArray.length(); i++) {

            JSONObject jsonObject = jsonArray.getJSONObject(i);


            String name = jsonObject.getString("nama");
            String description = jsonObject.getString("deskripsi");
            String latitude = jsonObject.getString("lat");
            String longitude = jsonObject.getString("lng");

            // Add marker
            addMarkerToMap(latitude, longitude, name, description);
        }

    } catch (JSONException e) {
        e.printStackTrace();
        Toast.makeText(mContext, "Error: " + e.getMessage(), Toast.LENGTH_LONG).show();
    }

}

public void addMarkerToMap(String latitude, String longitude, String title, String description)
{
    double lat = Double.parseDouble(latitude);
    double lng = Double.parseDouble(longitude);

    // create marker
    MarkerOptions marker = new MarkerOptions().position(new LatLng(lat, lng))
                                              .title(title)
                                              .snippet(description);

    // Marker icon
    marker.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));

    // Add marker to map
    mMap.addMarker(marker);
}

希望对你有帮助~

Answer 2

你必须用你的 json 字符串创建一个 JsonObject ，遍历它并获取所需的字段。