我在我的应用程序中使用谷歌地方自动填充建议。它工作正常，但我想改善其性能。当用户键入某个地点时，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;
}
}
}
答案 0 :(得分：4)
使用以下代码替换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拨打电话，而是从afterTextChanged发出呼叫，它减少了每个字符后的呼叫次数，从而减少了延迟。
尝试一下，它可能对你有所帮助。
答案 1 :(得分：1)
还有另一种方法，如上所述对我不起作用 替换你的＆＃39; addTextChangedListener＆＃39;用这个。
每次执行onTextChanged（）方法并取消先前分配的timertask时，这将创建一个新的计时器。
edit_destination.addTextChangedListener(new TextWatcher() {
Timer timer = new Timer();
int DELAY = 3000;
String chterm;
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// Cancel the timer if already running.
timer.cancel();
chterm = s.toString();
// (Optional) Check if length of query is greater than 3
if(s.length() >= 3) {
// Start a new timer and assign a TimerTask to it.
timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
Log.i("---final selected text---", "" + chterm);
// Getting url to the Google Places Autocomplete api
String url = getAutoCompleteUrl(chterm);
// Creating a DownloadTask to download Google Places matching "s"
placesDownloadTask = new DownloadTask(PLACES);
// Start downloading Google Places
// This causes to execute doInBackground() of DownloadTask class
placesDownloadTask.execute(url);
}
}, DELAY);
}
}
@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
}
});