我正在尝试从我的 mySQL 数据库在 Google Maps v2 上创建标记，但它不起作用。地图确实出现了，但没有标记。谁能告诉我哪里出了问题以及我需要改变什么？我也尝试过让 getDouble 成为 getDouble(0) 和 getDouble(1) 但我在某处读到尝试 0 和 2。它还从我尝试过的多个教程中导入了一堆。我稍后会删除。
我的活动
导入 com.google.android.gms.common.ConnectionResult；
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Dialog;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.widget.TextView;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class ReadComments extends FragmentActivity {
private static final String LOG_TAG = "JsOn ErRoR";
private static final String SERVICE_URL = "my url";
protected GoogleMap mapB;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.get_local);
setUpMapIfNeeded();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded() {
if (mapB == null) {
mapB = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapB))
.getMap();
if (mapB != null) {
setUpMap();
}
}
}
private void setUpMap() {
new Thread(new Runnable() {
public void run() {
try {
retrieveAndAddCities();
} catch (IOException e) {
Log.e(LOG_TAG, "Cannot retrive cities", e);
return;
}
}
}).start();
}
protected void retrieveAndAddCities() throws IOException {
HttpURLConnection conn = null;
final StringBuilder json = new StringBuilder();
try {
// Connect to the web service
URL url = new URL(SERVICE_URL);
conn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(conn.getInputStream());
// Read the JSON data into the StringBuilder
int read;
char[] buff = new char[1024];
while ((read = in.read(buff)) != -1) {
json.append(buff, 0, read);
}
} catch (IOException e) {
Log.e(LOG_TAG, "Error connecting to service", e);
throw new IOException("Error connecting to service", e);
} finally {
if (conn != null) {
conn.disconnect();
}
}
// Must run this on the UI thread since it's a UI operation.
runOnUiThread(new Runnable() {
public void run() {
try {
createMarkersFromJson(json.toString());
} catch (JSONException e) {
Log.e(LOG_TAG, "Error processing JSON", e);
}
}
});
}
void createMarkersFromJson(String json) throws JSONException {
JSONArray jsonArray = new JSONArray(json);
List<Marker> markers = new ArrayList<Marker>();
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObj = jsonArray.getJSONObject(i);
Marker marker = mapB.addMarker(new MarkerOptions()
.title(jsonObj.getString("business_name"))
.position(new LatLng(
jsonObj.getJSONArray("latlng").getDouble(0),
jsonObj.getJSONArray("latlng").getDouble(2)
))
);
markers.add(marker);
}
}
}
我的 url 的 JSON 输出
[{"business_name":"Wine Bar","latlng":["43.6894658949280400","-116.3533687591552700"],
"business_id":"2","distance":"23.0298400562551"},
{"business_name":"Apple Headquarters","latlng":["37.3324083200000000","-122.0304781500000000"],
"business_id":"3","distance":"23.0298400562551"}]
我的 Logcat（我不知道如何拉整个 log cat，但这些是错误）
08-21 00:00:27.371: E/JsOn ErRoR(357): at com..ReadComments.createMarkersFromJson(ReadComments.java:127)
08-21 00:00:27.371: E/JsOn ErRoR(357): at com..ReadComments$2.run(ReadComments.java:107)
部分截图
