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我想從json文件資產文件夾中脫機加載標記並將其顯示在地圖上。 以前我可以將標記顯示爲textview,但我無法在地圖上顯示它們。 該應用程序顯示地圖,但不顯示標記。android-如何在脫機顯示JSON文件的地圖上顯示標記?
我不知道爲什麼。
stations.json
[
{
"name": "JAVANMARDAN1",
"lat": 35.747394,
"lang": 51.267577
}
]
map.xml
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.google.android.gms.maps.SupportMapFragment"/>
MapsActivity
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private Marker marker;
private GoogleMap mMap;
public MapsActivity() throws JSONException {
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
new AsyncTaskGetMareker().execute();
}
public String getJSONFromAssets() {
String json = null;
try {
InputStream inputData = getAssets().open("stations.json");
int size = inputData.available();
byte[] buffer = new byte[size];
inputData.read(buffer);
inputData.close();
json = new String(buffer, "UTF-8");
} catch (IOException ex) {
ex.printStackTrace();
return null;
}
return json;
}
private class AsyncTaskGetMareker extends AsyncTask
<String , String, JSONArray>{
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected JSONArray doInBackground(String... strings) {
return null;
}
protected void onPostExecute (JSONArray result){
if (result !=null){
for (int i =0; i <result.length(); i++){
JSONObject jsonObject= null;
try {
jsonObject= result.getJSONObject(i);
String name=jsonObject.getString("name");
String lat=jsonObject.getString("lat");
String lang=jsonObject.getString("lang");
drawMarker(new LatLng(Double.parseDouble(lat),
Double.parseDouble(lang)));
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
private void drawMarker(LatLng point) {
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(point);
GoogleMap googleMap = null;
googleMap.addMarker(markerOptions);
}
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
}
}
太謝謝你了。有效 –