我需要在我的Android应用程序中构建一个搜索功能，它依赖于服务器的json响应。用户将在位于操作栏中的搜索视图中输入搜索查询。根据用户类型，将对服务器进行查询，并且服务器返回的响应应显示为下拉建议。我应该怎么做呢。根据我读过的文档，我需要实现一个内容提供者。什么是实现应用搜索的最佳方式？
答案 0 :(得分：9)
请参阅我为EditText实现的以下代码。您也可以执行以下操作：
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webservice以从服务器获取响应。 服务类是：
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方法你必须向你的活动发送广播，并且接收这个broadCast，你可以将你的Json数据保存到arrayList中。就像这样：
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();
}
}
我已经使用Json Object的arrayList设置了适配器，如下所示：
mOverlapAdapter = new RightOverlapAdapter(getBaseContext(),
mRightListOverlapData);
mDListRightOverLap.setAdapter(mOverlapAdapter);
您可以直接将具有指定标记的JSONObject的ArrayList中的数据读入适配器的getView方法。
您需要在Manifest中定义此服务，如下所示：
<service android:name="com.your.package.WebService" />
希望它会对你有所帮助。
答案 1 :(得分：2)
您可以为AutoCompleteTextView定制适配器。
...
getInput = (AutoCompleteTextView) rootView
.findViewById(R.id.translate_word);
getInput.setAdapter(new AutoCompleteAdapter(mContext));
...
AutoCompleteAdapter类
public class AutoCompleteAdapter extends ArrayAdapter<AutoCompleteItem> {
protected static final String TAG = "AutoCompleteAdapter";
private Context mContext;
private LayoutInflater vi;
private List<AutoCompleteItem> suggestions;
public AutoCompleteAdapter(Context context) {
super(context, R.layout.autocomplete_item);
this.mContext = context;
vi = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
suggestions = new ArrayList<AutoCompleteItem>();
}
@Override
public int getCount() {
return suggestions.size();
}
@Override
public AutoCompleteItem getItem(int index) {
return suggestions.get(index);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
final AutoCompleteItem i = suggestions.get(position);
if (i != null) {
AutoCompleteItem aci = (AutoCompleteItem)i;
v = vi.inflate(R.layout.autocomplete_item, null);
final TextView txtWord = (TextView)v.findViewById(R.id.word);
if (txtWord != null) {
txtWord.setText(aci.getWord());
}
final TextView txtLang = (TextView)v.findViewById(R.id.lang);
if (txtLang != null) {
if (aci.getLang() != null && !aci.getLang().equals(""))
txtLang.setText("[" + aci.getLang().toUpperCase() + "]");
}
final TextView txtConj = (TextView)v.findViewById(R.id.conj);
if (txtConj != null) {
txtConj.setText(aci.getConj());
txtConj.setTag(i);
txtConj.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AutoCompleteItem autoCompleteItem = (AutoCompleteItem)v.getTag();
String lang = autoCompleteItem.getLang();
// v.getParent().
String word = autoCompleteItem.getWord();
}
});
}
}
return v;
}
@Override
public Filter getFilter() {
Filter myFilter = new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if (constraint != null && !constraint.toString().equalsIgnoreCase(sWord) && constraint.toString().length() >= 2) {
AutoCompleteParse acp = new AutoCompleteParse();
// A class that queries a web API, parses the data and
// returns an ArrayList<AutoCompleteItem>
List<AutoCompleteItem> new_suggestions =acp.getAutoComplete(mContext, constraint.toString());
suggestions.clear();
for (int i=0;i<new_suggestions.size();i++) {
suggestions.add(new_suggestions.get(i));
}
if (suggestions.size() > 0) sWord = constraint.toString();
// Now assign the values and count to the FilterResults
// object
filterResults.values = suggestions;
filterResults.count = suggestions.size();
}
return filterResults;
}
@Override
protected void publishResults(CharSequence contraint,
FilterResults results) {
if (contraint != null && !contraint.toString().equalsIgnoreCase(sWord) && contraint.toString().length() >= 2
&& results != null && results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
};
return myFilter;
}
}
AutoCompleteParse类
public class AutoCompleteParse {
Context mContext;
public AutoCompleteParse() {
}
public List<AutoCompleteItem> getAutoComplete(Context context, String sWord) {
this.mContext = context;
...
List<AutoCompleteItem> ListData = new ArrayList<AutoCompleteItem>();
try {
URL acUrl = new URL(autoCompleteUrl);
URLConnection acConn = acUrl.openConnection();
BufferedReader reader = new BufferedReader(new InputStreamReader(
acConn.getInputStream()));
String line = reader.readLine();
do {
...
} while (line != null);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return ListData;
}