Question

我正在尝试启动一个新线程，在解析JSON响应并将其存储在hashmap中之后在地图上添加标记。完成此异步任务后，我想通过迭代hashmap值并使用addMarkers()在地图上添加新标记。当我运行我的应用程序时它崩溃了，我收到了这个错误。

Logcat错误：

at com.google.k.a.cj.b(Unknown Source)
at com.google.maps.api.android.lib6.c.ca.a(Unknown Source)
at com.google.maps.api.android.lib6.c.el.a(Unknown Source)
at com.google.android.gms.maps.internal.l.onTransact(SourceFile:167)
at android.os.Binder.transact(Binder.java:361)
at com.google.android.gms.maps.internal.IGoogleMapDelegate$a$a.addMarker(Unknown Source)
at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
at com.example.test.testapp.MapsActivity$ParseJSON$1.run(MapsActivity.java:169)

MapsActivity

public class ParseJSON extends AsyncTask<String, Void, Void>
{
    @Override
    protected Void doInBackground(String... params)
    {
        try
        {
            HttpClient client = new DefaultHttpClient();
            HttpPost post = new HttpPost(params[0]);

            HttpResponse response = client.execute(post);
            int status = response.getStatusLine().getStatusCode();
            if(status == 200)
            {
                HttpEntity entity = response.getEntity();
                String data = EntityUtils.toString(entity);

                String noHTML = stripHtml(data);

                JSONArray jsonArray = new JSONArray(noHTML);

                for(int i = 0; i < jsonArray.length(); i++)
                {
                    NearbyStops stops = new NearbyStops();
                    JSONObject jsonObject = jsonArray.getJSONObject(i);
                    String id = jsonObject.getString("ID");
                    stops.name = jsonObject.getString("Name");
                    stops.lat = jsonObject.getDouble("Lat");
                    stops.lng = jsonObject.getDouble("Long");

                    stopHash.put(id, stops);
                }
            }
        }
        catch (ClientProtocolException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        catch (JSONException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result)
    {
        Thread addMarkers = new Thread(new Runnable()
        {
            @Override
            public void run()
            {
                for(NearbyStops value : stopHash.values())
                {
                    MarkerOptions markerOptions = new MarkerOptions();

                    String name = value.name;
                    double lat = value.lat;
                    double lng = value.lng;

                    LatLng latLng = new LatLng(lat, lng);
                    markerOptions.position(latLng);
                    markerOptions.title(name);
                    mMap.addMarker(markerOptions);
                }
            }
        });
        addMarkers.start();
    }
}

Answer 1

我怀疑，因为您正在工作线程上访问mMap Google地图对象。所以，只需删除addMarkers Thread中的onPostExecute()，然后直接在onPostExceute()中添加标记，然后在stopHash线程中引用一些像addMarker这样的对象。无法访问（表示您引用的stopHash中没有值，或者可能是null）。

尝试运行新线程以添加Google地图标记时崩溃

1 个答案: