android - 如何提高谷歌地点自动完成建议的性能？

Question

我在我的应用程序中使用 google places autocomplete suggestions。它工作正常，但我想提高它的性能。当用户输入一个地方时，它会在长时间延迟后或有时在删除最后一个字符后给出建议。我如何提高它的性能？请帮我。提前致谢

这是我的代码

public class invoice extends Activity
{

AutoCompleteTextView edit_destination;
DownloadTask placesDownloadTask;
DownloadTask placeDetailsDownloadTask;
ParserTask placesParserTask;
ParserTask placeDetailsParserTask;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub    
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.create_invoice_activity);

edit_destination=(AutoCompleteTextView) findViewById(R.id.destination);
    edit_destination.setThreshold(1);       

    edit_destination.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {   
            // Creating a DownloadTask to download Google Places matching "s"
            placesDownloadTask = new DownloadTask(PLACES);

            // Getting url to the Google Places Autocomplete api
            String url = getAutoCompleteUrl(s.toString());

            // Start downloading Google Places
            // This causes to execute doInBackground() of DownloadTask class
            placesDownloadTask.execute(url);
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub
        }

        @Override
        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub              
        }
    }); 

    edit_destination.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int index,
                        long id) {

                ListView lv = (ListView) arg0;
                SimpleAdapter adapter = (SimpleAdapter) arg0.getAdapter();

                HashMap<String, String> hm = (HashMap<String, String>) adapter.getItem(index);


                selected_place=hm.get("description");


                // Creating a DownloadTask to download Places details of the selected place
                placeDetailsDownloadTask = new DownloadTask(PLACES_DETAILS);

                // Getting url to the Google Places details api
                String url = getPlaceDetailsUrl(hm.get("reference"));                   

                // Start downloading Google Place Details
                // This causes to execute doInBackground() of DownloadTask class
                placeDetailsDownloadTask.execute(url);

        }
    });     

}


private String getAutoCompleteUrl(String place){

        // Obtain browser key from https://code.google.com/apis/console
        String key = "YOUR KEY";

        // place to be be searched
        String input = "input="+place;

        // place type to be searched
        String types = "types=geocode";

        // Sensor enabled
        String sensor = "sensor=false";         

        // Building the parameters to the web service
        String parameters = input+"&"+types+"&"+sensor+"&"+key;

        // Output format
        String output = "json";

        // Building the url to the web service
        String url = "https://maps.googleapis.com/maps/api/place/autocomplete/"+output+"?"+parameters;

        return url;
    }


    private String getPlaceDetailsUrl(String ref){

        // Obtain browser key from https://code.google.com/apis/console
        String key = "YOUR KEY";

        // reference of place
        String reference = "reference="+ref;                    

        // Sensor enabled
        String sensor = "sensor=false";         

        // Building the parameters to the web service
        String parameters = reference+"&"+sensor+"&"+key;

        // Output format
        String output = "json";

        // Building the url to the web service
        String url = "https://maps.googleapis.com/maps/api/place/details/"+output+"?"+parameters;

        return url;
    }

    /** A method to download json data from url */
    private String downloadUrl(String strUrl) throws IOException{
        String data = "";
        InputStream iStream = null;
        HttpURLConnection urlConnection = null;
        try{
                URL url = new URL(strUrl);

                // Creating an http connection to communicate with url 
                urlConnection = (HttpURLConnection) url.openConnection();

                // Connecting to url 
                urlConnection.connect();

                // Reading data from url 
                iStream = urlConnection.getInputStream();

                BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

                StringBuffer sb  = new StringBuffer();

                String line = "";
                while( ( line = br.readLine())  != null){
                        sb.append(line);
                }

                data = sb.toString();

                br.close();

        }catch(Exception e){
                Log.d("Exception while downloading url", e.toString());
        }finally{
                iStream.close();
                urlConnection.disconnect();
        }
        return data;
     }


    // Fetches data from url passed
    private class DownloadTask extends AsyncTask<String, Void, String>{

        private int downloadType=0;

        // Constructor
        public DownloadTask(int type){
        this.downloadType = type;

        }

        @Override
        protected String doInBackground(String... url) {

            // For storing data from web service
            String data = "";

            try{
                // Fetching the data from web service
                data = downloadUrl(url[0]);
            }catch(Exception e){
                Log.d("Background Task",e.toString());
            }
            return data;        
        }

        @Override
        protected void onPostExecute(String result) {           
            super.onPostExecute(result);        

            switch(downloadType){
            case PLACES:
                // Creating ParserTask for parsing Google Places
                placesParserTask = new ParserTask(PLACES);

                // Start parsing google places json data
                // This causes to execute doInBackground() of ParserTask class
                System.out.println(result);
                placesParserTask.execute(result);

                break;

            case PLACES_DETAILS : 
                // Creating ParserTask for parsing Google Places
                placeDetailsParserTask = new ParserTask(PLACES_DETAILS);

                // Starting Parsing the JSON string
                // This causes to execute doInBackground() of ParserTask class
                placeDetailsParserTask.execute(result);                             
            }           
        }       
    }     


    /** A class to parse the Google Places in JSON format */
    private class ParserTask extends AsyncTask<String, Integer, List<HashMap<String,String>>>{

        int parserType = 0;

        public ParserTask(int type){
            this.parserType = type;
        }

        @Override
        protected List<HashMap<String, String>> doInBackground(String... jsonData) {

            JSONObject jObject;         
            List<HashMap<String, String>> list = null;           

            try{
                jObject = new JSONObject(jsonData[0]);

                switch(parserType){
                case PLACES :
                    PlaceJSONParser placeJsonParser = new PlaceJSONParser();
                    // Getting the parsed data as a List construct
                    list = placeJsonParser.parse(jObject);
                    break;
                case PLACES_DETAILS :                       
                    PlaceDetailsJSONParser placeDetailsJsonParser = new PlaceDetailsJSONParser();
                    // Getting the parsed data as a List construct
                    list = placeDetailsJsonParser.parse(jObject);
                }

            }catch(Exception e){
                Log.d("Exception",e.toString());
            }
            return list;
        }

        @Override
        protected void onPostExecute(List<HashMap<String, String>> result) {

                switch(parserType){
                case PLACES :
                    String[] from = new String[] { "description"};
                    int[] to = new int[] { android.R.id.text1 };

                    // Creating a SimpleAdapter for the AutoCompleteTextView
                    SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), result, android.R.layout.simple_list_item_1, from, to);             

                    // Setting the adapter
                    edit_destination.setAdapter(adapter);                       
                    break;
                case PLACES_DETAILS :                       
                    HashMap<String, String> hm = result.get(0);

                    // Getting latitude from the parsed data 
                     latitude = Double.parseDouble(hm.get("lat"));

                    System.out.println(latitude);

                    // Getting longitude from the parsed data
                     longitude = Double.parseDouble(hm.get("lng"));     
                    System.out.println(longitude);


                    Toast.makeText(invoice.this, latitude+","+longitude , Toast.LENGTH_LONG).show();



                    SharedPreferences pref=getSharedPreferences("LOC", 0);


                    String S_lat,S_long;
                   S_lat=pref.getString("LAT", "");
                   S_long= pref.getString("LONG",""); 

                    source_lat=Double.parseDouble(S_lat);
                    source_long=Double.parseDouble(S_long);








                    break;                      
                }           
        }           
    }        

Answer 1

用以下代码替换 autocompleteTextView 的“addTextChangedListener”方法...

edit_destination.setOnKeyListener(new OnKeyListener() {
    public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
        return false;
    }

});
edit_destination.addTextChangedListener(new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {   
        // Creating a DownloadTask to download Google Places matching "s"

        if(placesDownloadTask!=null)
        {                        
              Log.i("--placesDownloadTask--","progress_status : "+placesDownloadTask.getStatus());
              placesDownloadTask.cancel(true);      
        }


    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
        // TODO Auto-generated method stub

    }

    @Override
    public void afterTextChanged(Editable s) {
        // TODO Auto-generated method stub      
        String chterm; 
        chterm=edit_destination.getText().toString();
        Log.i("---final selected text---", ""+chterm);
        placesDownloadTask = new DownloadTask(PLACES);

        // Getting url to the Google Places Autocomplete api
        String url = getAutoCompleteUrl(s.toString());

        // Start downloading Google Places
        // This causes to execute doInBackground() of DownloadTask class
        placesDownloadTask.execute(url);
    }
});

不是从 onTextChanged 发出调用，而是从 afterTextChanged 发出调用，它减少了每个字符后的调用次数，从而减少了延迟。

试试吧，它可能对你有很大帮助。