Question

我正在使用Android Studio开发一个应用程序，该应用程序提供犯罪已提交的信息和XAMPP Server。我刚刚加载谷歌地图，现在我想从MySQL数据库加载坐标（Lat＆amp; Long）并在地图视图中将其显示为标记。我按照androidhive的教程。 http://www.androidhive.info/2013/08/android-working-with-google-maps-v2/

有人可以请我提供一些教程或对此问题的参考。我非常需要一些帮助来完成我的项目，因为这是我论文课程的要求。提前谢谢。

这是我的地图活动代码：

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;

public class MapActivity extends Activity {

    // Google Map
    private GoogleMap googleMap;

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

        // Create button
        Button home = (Button) findViewById(R.id.btn_home);
        home.setOnClickListener(new View.OnClickListener() {
            public void onClick(View arg0) {
                Intent intent = new Intent(
                        MapActivity.this,
                        MainActivity.class);
                startActivity(intent);
            }
        });

        try {
            // Loading map
            initilizeMap();

            // Changing map type
            googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
            // googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
            // googleMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
            // googleMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
            // googleMap.setMapType(GoogleMap.MAP_TYPE_NONE);

            // Showing / hiding your current location
            googleMap.setMyLocationEnabled(true);

            // Enable / Disable zooming controls
            googleMap.getUiSettings().setZoomControlsEnabled(false);

            // Enable / Disable my location button
            googleMap.getUiSettings().setMyLocationButtonEnabled(true);

            // Enable / Disable Compass icon
            googleMap.getUiSettings().setCompassEnabled(true);

            // Enable / Disable Rotate gesture
            googleMap.getUiSettings().setRotateGesturesEnabled(true);

            // Enable / Disable zooming functionality
            googleMap.getUiSettings().setZoomGesturesEnabled(true);

            double latitude = 14.5954076;
            double longitude = 120.9883922;


                // Move the camera to last position with a zoom level
                if (i == 9) {
                    CameraPosition cameraPosition = new CameraPosition.Builder()
                            .target(new LatLng(randomLocation[0],
                                    randomLocation[1])).zoom(16).build();

                    googleMap.animateCamera(CameraUpdateFactory
                            .newCameraPosition(cameraPosition));
                }

                // Polylines are useful for marking paths and routes on the map.
                googleMap.addPolyline(new PolylineOptions().geodesic(true)
                                .add(new LatLng(14.596046, 120.989171))
                                .add(new LatLng(14.596155, 120.988686))
                                .add(new LatLng(14.595890, 120.988627))
                                .add(new LatLng(14.595991, 120.988074))
                                .add(new LatLng(14.595724, 120.988015))
                                .add(new LatLng(14.596151, 120.986254))
                                .add(new LatLng(14.595351, 120.986125))
                                .add(new LatLng(14.595162, 120.987067))
                                .add(new LatLng(14.595060, 120.987289))
                                .add(new LatLng(14.594383, 120.988190))
                                .add(new LatLng(14.596052, 120.989169))
                );
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    @Override
    protected void onResume() {
        super.onResume();
        initilizeMap();
    }

    /**
     * function to load map If map is not created it will create it for you
     * */
    private void initilizeMap() {
        if (googleMap == null) {
            googleMap = ((MapFragment) getFragmentManager().findFragmentById(
                    R.id.map)).getMap();

            // check if map is created successfully or not
            if (googleMap == null) {
                Toast.makeText(getApplicationContext(),
                        "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                        .show();
            }
        }
    }

    /*
     * creating random postion around a location for testing purpose only
     */
    private double[] createRandLocation(double latitude, double longitude) {

        return new double[] { latitude + ((Math.random() - 0.5) / 500),
                longitude + ((Math.random() - 0.5) / 500),
                100 + ((Math.random() - 0.5) * 10) };
    }

}

和我的XML代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:layout="@layout/activity_map" />

    <Button
        android:id="@+id/btn_home"
        android:layout_width="45dp"
        android:layout_height="45dp"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_marginTop="55dp"
        android:layout_marginRight="7dp"
        android:background="@drawable/ic_home"/>

</RelativeLayout>

JSON解析器（用于HTTP客户端请求）：

import android.util.Log;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    // function get json from url
    // by making HTTP POST or GET mehtod
    public JSONObject makeHttpRequest(String url, String method,
            List<NameValuePair> params) {

        // Making HTTP request
        try {

            // check for request method
            if(method == "POST"){
                // request method is POST
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                httpPost.setEntity(new UrlEncodedFormEntity(params));

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            }else if(method == "GET"){
                // request method is GET
                DefaultHttpClient httpClient = new DefaultHttpClient();
                String paramString = URLEncodedUtils.format(params, "utf-8");
                url += "?" + paramString;
                HttpGet httpGet = new HttpGet(url);

                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }           


        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

Answer 1

首先，您需要从MySQL Db获取坐标，因此您必须建立网络连接以获取数据。要创建网络连接，有两种方法

Choose you HttpClient and perform network request yourself
Use any library for network connection(Volley)

现在假设您现在拥有数据或坐标，然后调用该方法 MapFragment.getMapAsync(OnMapReadyCallBack)

现在，地图准备就绪，您将收到GoogleMap的对象，然后您可以在其上添加标记。即。

@Override
 public void onMapReady(GoogleMap map) {
        map.addMarker(new MarkerOptions()
        .position(new LatLng(0, 0))
        .title("Marker"));

}

Answer 2

是的，这是可能的

googleMap.addMarker(new MarkerOptions()
            .position(BROOKLYN_BRIDGE)
            .title("First Pit Stop")
            .icon(BitmapDescriptorFactory
            .defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));

供参考使用 link

是否可以从MySQL数据库加载坐标并在Android Google地图中显示为标记

2 个答案: