android:根据服务器响应实现应用程序搜索建议

Question

我需要在我的 android 应用程序中构建一个搜索功能，它依赖于来自服务器的 json 响应。用户将在位于操作栏中的搜索 View 中输入搜索查询。根据用户键入的内容，将对服务器进行查询，服务器返回的响应应显示为下拉建议。我该怎么办。根据我阅读过的文档，我需要实现一个内容提供者。实现应用搜索的最佳方式是什么？

Answer 1

请参阅下面我为 EditText 实现的代码。您也可以这样做:

private ArrayList<JSONObject> mRightListOverlapData, mRightTempData;
mEdit_Search.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {


        }

        @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
            mRightListOverlapData.clear();
            String searchTag = mEdit_Search.getText().toString();
            if (searchTag == null || searchTag.equals("")) {


                mRightTempData.clear();
                mOverlapAdapter.notifyDataSetChanged();

            } else if (searchTag.length() == 1) {

                    mRightListOverlapData.addAll(mRightTempData);



                    mOverlapAdapter.notifyDataSetChanged();
                } else {
                    **startServiceForSearchSuggestion(searchTag);**
                }


            } else {

                try {
                    if (mRightTempData.size() > 0) {

                        for (int i = 0; i < mRightTempData.size(); i++) {
                            if (mRightTempData.get(i)
                                    .getString("search_text").toLowerCase()
                                    .startsWith(searchTag.toLowerCase())) {
                                mRightListOverlapData.add(mRightTempData
                                        .get(i));
                            }
                        }
                        if (mRightListOverlapData.size() == 0) {
                            JSONObject noData = new JSONObject();
                            noData.put("search_text", "No Data");
                            mRightListOverlapData.add(noData);

                        }
                    }

                    mOverlapAdapter.notifyDataSetChanged();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
        }
    });

当用户在 EditText 中输入第一个字符时，它将调用 webService。然后将所有响应保存到 tempArray 中，当用户输入另一个字符时，它将从 tempArray 中搜索该元素。方法 startServiceForSearchSuggestion() 是:

private void startServiceForSearchSuggestion(String search_tag) {
    if (!Utils.isNetworkAvailable(getBaseContext())) {
        Toast.makeText(getBaseContext(), "No Network Available",
                Toast.LENGTH_SHORT).show();
    } else {
        Intent intent1 = new Intent(this, WebService.class);
        intent1.putExtra(METHOD, GET_SEARCH_SUGGESTION);
        intent1.putExtra("search_tag", search_tag);
        startService(intent1);
    }
}

它将启动网络服务以从服务器获取响应。服务等级是:

 public class WebService extends Service implements WebServiceConstants {
    private AppPreferences mPrefs;
    private static String TAG_WEB_SERVICE = "WebService";
    private static String DEVICE_TYPE = "android";
    private static String MESSAGE_CENTER = "gcm";
    private static String URL_JSON = "YOUR_URL";
    private Context mContext;
    private int METHOD_NAME = 1;
    private String mSearch_Tag = "";
    private DBQuery mDBQuery;
    public static boolean is_Service_Running = false;

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        mContext = this;
        mPrefs = new AppPreferences(mContext);
        mDBQuery = new DBQuery(mContext);

    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onStart(Intent intent, int startId) {
        // TODO Auto-generated method stub
        try {
            METHOD_NAME = intent.getIntExtra(METHOD, 1);

                mSearch_Tag = intent.getStringExtra("search_tag");

            LoadDataFromServer data = new LoadDataFromServer();
            data.execute();
        } catch (NullPointerException e) {
            // TODO: handle exception
        }
        super.onStart(intent, startId);
    }

public class LoadDataFromServer extends AsyncTask<Void, Void, Void> {
        JSONObject response;

        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub
            JSONObject root = getJsonHeader();
            switch (METHOD_NAME) {


            case GET_SEARCH_SUGGESTION:
                response = getResponse(yourJsonRequestObject);
                break;

            }

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            // TODO Auto-generated method stub
            try {

                switch (METHOD_NAME) {


                case GET_SEARCH_SUGGESTION:
                    Log.v(TAG_WEB_SERVICE,
                            "Response = GET_SEARCH_SUGGESTION : "
                                    + response.toString());
                    sendBroadcast(new Intent(METHOD_GET_SEARCH_SUGGESTION)
                            .putExtra("Response", response.toString()));

                    break;

                default:
                    break;
                }
            } catch (NullPointerException e) {
                // TODO: handle exception
            }

        }

    }
    }

onPostExecute 方法你必须发送广播到你的 Activity 和 onReceive 这个 broadCast 你可以将你的 Json 数据保存到 arrayList 中。像这样:

private BroadcastReceiver mReceiverSearchSuggestion = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            // TODO Auto-generated method stub
            JSONObject root;
            try {
                root = new JSONObject(intent.getStringExtra("Response"));
                setSearchSuggestions(root);
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    };

方法:

1.

private JSONObject getResponse(JSONObject obj) {
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpParams myParams = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(myParams, 10000);
        HttpConnectionParams.setSoTimeout(myParams, 10000);
        String temp = "";

        try {

            HttpPost httppost = new HttpPost(URL_JSON);
            httppost.setHeader("Content-type", "application/json");
            StringEntity se = new StringEntity(obj.toString());
            se.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE,
                    "application/json"));
            httppost.setEntity(se);

            HttpResponse response = httpclient.execute(httppost);
            temp = EntityUtils.toString(response.getEntity());
            Log.v(TAG_WEB_SERVICE, "Temp = " + temp);
            if (temp == null || temp.trim().equals("")) {

            } else {
                return new JSONObject(temp);
            }
        } catch (ClientProtocolException e) {

        } catch (IOException e) {

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

2.

private void setSearchSuggestions(JSONObject root) {
        // TODO Auto-generated method stub
        try {
            JSONObject search_suggestion = root
                    .getJSONObject(METHOD_GET_SEARCH_SUGGESTION);
            if (search_suggestion.getString("response_type").equalsIgnoreCase(
                    "success")) {
                if (search_suggestion.has("data")) {
                    mRightTempData.clear();
                    mRightListOverlapData.clear();
                    JSONArray data = search_suggestion.getJSONArray("data");
                    for (int i = 0; i < data.length(); i++) {
                        JSONObject value = data.getJSONObject(i);

                        mRightTempData.add(value);
                    }

                } else {
                    Toast.makeText(getBaseContext(),
                            "No data related to search", Toast.LENGTH_SHORT)
                            .show();
                }
            } else {
                Toast.makeText(getBaseContext(),
                        "Search Suggestion : Type Failure", Toast.LENGTH_SHORT)
                        .show();
            }


    }

我已经像这样用 Json 对象的 arrayList 设置了适配器:

        mOverlapAdapter = new RightOverlapAdapter(getBaseContext(),
            mRightListOverlapData);

    mDListRightOverLap.setAdapter(mOverlapAdapter);

您可以直接从带有指定标签的JSONObject的ArrayList中读取数据到您的适配器的getView方法中。

您需要像这样在 Manifest 中定义此服务:

 <service android:name="com.your.package.WebService" />

希望对你有所帮助。