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？
最佳答案
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。
关于android:根据服务器响应实现应用程序搜索建议，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21375449/