在 google 地图 android 上显示位置

Question

我有一个 EditText 和一个 Button 我想在地图上找到位置。我正在使用 AsyncTask 来执行这里是我调用 AsyncTask class。当我使用 Toast msg 它显示我的位置但在地图中它被强制关闭

new GeocoderTask().execute(location);
Toast.makeText(getApplicationContext(), location, Toast.LENGTH_LONG).show();

这是我的 GeocoderTask class 在地图中显示位置

private class GeocoderTask extends AsyncTask<String, Void, List<Address>>{

            @Override
            protected List<Address> doInBackground(String... locationName) {
                // Creating an instance of Geocoder class
                Geocoder geocoder = new Geocoder(getBaseContext());
                List<Address> addresses = null;

                try {
                    // Getting a maximum of 3 Address that matches the input text
                    addresses = geocoder.getFromLocationName(locationName[0], 3);
                } catch (IOException e) {
                    e.printStackTrace();
                }           
                return addresses;
            }


            @Override
            protected void onPostExecute(List<Address> addresses) {         

                if(addresses==null || addresses.size()==0){
                    Toast.makeText(getBaseContext(), "No Location found", Toast.LENGTH_SHORT).show();
                }

                // Clears all the existing markers on the map
                googleMap.clear();

                // Adding Markers on Google Map for each matching address
                for(int i=0;i<addresses.size();i++){                

                    Address address = (Address) addresses.get(i);

                    // Creating an instance of GeoPoint, to display in Google Map
                    latLng = new LatLng(address.getLatitude(), address.getLongitude());

                    String addressText = String.format("%s, %s",
                            address.getMaxAddressLineIndex() > 0 ? address.getAddressLine(0) : "",
                            address.getCountryName());

                    markerOptions = new MarkerOptions();
                    markerOptions.position(latLng);
                    markerOptions.title(addressText);

                    googleMap.addMarker(markerOptions);

                    // Locate the first location
                    if(i==0)                        
                        googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));     
                }           
            }       
        }
}

但是不显示位置。

Answer 1

假设你在行 new Geocoder(getBaseContext()); 中出错，所以建议你使用构造函数将 Context 传递给 AsyncTask:

private class GeocoderTask extends AsyncTask<String, Void, List<Address>>{

        private Context mContext;
        public GeoCoderTask(Context context) {
            super();
            mContext = context;
        }


        @Override
        protected List<Address> doInBackground(String... locationName) {
            // Creating an instance of Geocoder class
            Geocoder geocoder = new Geocoder(mContext);

            ... ...

        }
}

希望对您有所帮助！

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