需要帮助遵循谷歌地图API上的教程以进行自动完成

Question

我正在尝试在我的应用程序中使用自动完成功能。

搜索了一段时间后，我找到了以下教程：

http://www.claytical.com/blog/android-dynamic-autocompletion-using-google-places-api

有一个名为 s 的未解析变量，其中创建了 URL：

URLEncoder.encode(s.toString(), "UTF-8") +

我不明白这个变量是从哪里来的。

这里几乎是本教程中的整个代码，经过了一些调整。

public class PlacesListSearchActivity extends Activity {
    private static final String TAG = "PlacesListActivity";
    public ArrayAdapter<String> adapter;
    public AutoCompleteTextView textView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.places_search);
        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.item_list);
        final AutoCompleteTextView textView = (AutoCompleteTextView)
        findViewById(R.id.autoCompleteTextView1);
        adapter.setNotifyOnChange(true);
        textView.setAdapter(adapter);
        textView.addTextChangedListener(new TextWatcher() {
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if (count%3 == 1) {
                adapter.clear();
                    GetPlaces task = new GetPlaces();
                    //now pass the argument in the textview to the task
                    task.execute(textView.getText().toString());
            }
        }
        public void beforeTextChanged(CharSequence s, int start, int count,
        int after) {
        // TODO Auto-generated method stub
        }
        public void afterTextChanged(Editable s) {
        }
        });
    }
    class GetPlaces extends AsyncTask<String, Void, ArrayList<String>> {
        @Override
        // three dots is java for an array of strings
        protected ArrayList<String> doInBackground(String... args)
        {
            Log.d("gottaGo", "doInBackground");
            ArrayList<String> predictionsArr = new ArrayList<String>();
            try
            {
                //https://maps.googleapis.com/maps/api/place/autocomplete/json?input=Vict&types=geocode&language=fr&sensor=true&key=AddYourOwnKeyHere
                URL googlePlaces = new URL(
                        "https://maps.googleapis.com/maps/api/place/autocomplete/json?input=" +
                        URLEncoder.encode(s.toString(), "UTF-8") +
                        "&types=geocode&language=en&sensor=true&key=" +
                        getResources().getString(R.string.googleAPIKey));
                URLConnection tc = googlePlaces.openConnection();
                BufferedReader in = new BufferedReader(new InputStreamReader(
                        tc.getInputStream()));
                String line;
                StringBuffer sb = new StringBuffer();
                //take Google's legible JSON and turn it into one big string.
                while ((line = in.readLine()) != null) {
                    sb.append(line);
                }
                //turn that string into a JSON object
                JSONObject predictions = new JSONObject(sb.toString()); 
                //now get the JSON array that's inside that object            
                JSONArray ja = new JSONArray(predictions.getString("predictions"));
                for (int i = 0; i < ja.length(); i++) {
                    JSONObject jo = (JSONObject) ja.get(i);
                    //add each entry to our array
                    predictionsArr.add(jo.getString("description"));
                }
            } catch (IOException e)
            {
            Log.e("YourApp", "GetPlaces : doInBackground", e);
            } catch (JSONException e)
            {
            Log.e("YourApp", "GetPlaces : doInBackground", e);
            }
            return predictionsArr;
        }
        //then our post
        @Override
        protected void onPostExecute(ArrayList<String> result){
        Log.d("YourApp", "onPostExecute : " + result.size());
        //update the adapter
        adapter = new ArrayAdapter<String>(getBaseContext(), R.layout.item_list);
        adapter.setNotifyOnChange(true);
        //attach the adapter to textview
        textView.setAdapter(adapter);
        for (String string : result) {
            Log.d("YourApp", "onPostExecute : result = " + string);
            adapter.add(string);
            adapter.notifyDataSetChanged();
        }
        Log.d("YourApp", "onPostExecute : autoCompleteAdapter" + adapter.getCount());
        }
    }
}

好的，我回答了我自己的问题。请参阅下面的答案！

Answer 1

好的，我知道了。上面的 URL 应按以下方式计算：

            URL googlePlaces = new URL(
                    "https://maps.googleapis.com/maps/api/place/autocomplete/json?input=" +
                    URLEncoder.encode(args[0], "UTF-8") +
                    "&types=geocode&language=en&sensor=true&key=" +
                    getResources().getString(R.string.googleAPIKey));