从 JSON 填充 Listview
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【中文标题】从 JSON 填充 Listview【英文标题】：Populate Listview from JSON 【发布时间】：2011-09-10 18:04:53 【问题描述】：有谁知道动态加载 Json 的任何示例 数据到 ListView，我见过的大多数例子只是使用 某种静态数组。我需要加载 10 行 Json 数据，然后在底部有一个负载更多.. 以获取 接下来的10个等等等等。 请使用 Json 的示例....
【问题讨论】：
我正在处理类似的案例，如果您找到任何解决方案，请在此处发布！ 【参考方案1】：程序员布鲁斯是正确的，没有默认的方法可以做到这一点。但是，有一种非常干净和简单的方法可以完成此任务。这是我用来处理 JSONArrays 的适配器。
class JSONAdapter extends BaseAdapter implements ListAdapter
private final Activity activity;
private final JSONArray jsonArray;
private JSONAdapter(Activity activity, JSONArray jsonArray)
assert activity != null;
assert jsonArray != null;
this.jsonArray = jsonArray;
this.activity = activity;
@Override public int getCount()
return jsonArray.length();
@Override public JSONObject getItem(int position)
return jsonArray.optJSONObject(position);
@Override public long getItemId(int position)
JSONObject jsonObject = getItem(position);
return jsonObject.optLong("id");
@Override public View getView(int position, View convertView, ViewGroup parent)
if (convertView == null)
convertView = activity.getLayoutInflater().inflate(R.layout.row, null);
JSONObject jsonObject = getItem(position);
return convertView;
【讨论】：
你不应该在生产级代码中有assert。 VenuesAdapter 是错字吗？
尝试复制粘贴，报错，能否举例说明如何使用此代码？
你能发布 R.layout.row 吗？【参考方案2】：
android 没有现成的适配器来用 JSON 数组填充 ListView，就像用数据库记录填充 ListView 一样。
我建议习惯于使用 JSON 数据填充您选择的 Java 数据结构，并习惯于使用 ListViews，使用不同的自定义行从不同的集合中填充它们。
这是一个从 JSON 数组填充List，然后使用List 填充ListView 的简单示例。
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class Main extends Activity
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
try
String jsonInput = "[\"one\",\"two\",\"three\",\"four\",\"five\",\"six\",\"seven\",\"eight\",\"nine\",\"ten\"]";
JSONArray jsonArray = new JSONArray(jsonInput);
int length = jsonArray.length();
List<String> listContents = new ArrayList<String>(length);
for (int i = 0; i < length; i++)
listContents.add(jsonArray.getString(i));
ListView myListView = (ListView) findViewById(R.id.my_list);
myListView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listContents));
catch (Exception e)
// this is just an example
【讨论】：
【参考方案3】：dbaugh 有一个很好的答案，但 this 的帖子解释了如何为我们其他不知道从那里去哪里的人使用它。
【讨论】：
【参考方案4】：试试下面的：
JSON 解析器类：
public class JSONParser
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser()
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params)
// Making HTTP request
try
// check for request method
if (method == "POST")
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
else if (method == "GET")
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
catch (UnsupportedEncodingException e)
e.printStackTrace();
catch (ClientProtocolException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
try
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
sb.append(line + "\n");
is.close();
json = sb.toString();
catch (Exception e)
Log.e("Buffer Error", "Error converting result " + e.toString());
// try parse the string to a JSON object
try
jObj = new JSONObject(json);
catch (JSONException e)
Log.e("JSON Parser", "Error parsing data " + e.toString());
// return JSON String
return jObj;
显示 Listview 的片段类：
public static class EventFragment extends ListFragment
ArrayList<HashMap<String, String>> eventsList;
private String url_all_events = //url goes here;
private ProgressDialog pDialog;
JSONParser jParser = new JSONParser();
// JSON Node names
private static final String CONNECTION_STATUS = "success";
private static final String TABLE_EVENT = "Event";
private static final String pid = "pid";
private static final String COL_GROUP = "Group";
private static final String COL_NAME = "Event_Name";
private static final String COL_DESC = "Event_Desc";
private static final String COL_DATE = "Event_Date";
private static final String COL_TIME = "Event_Time";
JSONArray Events = null;
public static final String ARG_SECTION_NUMBER = "section_number";
public EventFragment()
public void onStart()
super.onStart();
eventsList = new ArrayList<HashMap<String, String>>();
new LoadAllEvents().execute();
// selecting single ListView item
ListView lv = getListView();
// Lauching the Event details screen on selecting a single event
lv.setOnItemClickListener(new OnItemClickListener()
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id)
// getting values from selected ListItem
String ID = ((TextView) view.findViewById(R.id.pid))
.getText().toString();
Intent intent = new Intent(view.getContext(),
EventDetails.class);
intent.putExtra(pid, ID);
view.getContext().startActivity(intent);
);
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
View rootView = inflater.inflate(R.layout.fragment_events,
container, false);
return rootView;
class LoadAllEvents extends AsyncTask<String, String, String>
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute()
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Just a moment...");
pDialog.setIndeterminate(true);
pDialog.setCancelable(true);
pDialog.show();
protected String doInBackground(String... args)
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_events,
"GET", params);
try
// Checking for SUCCESS TAG
int success = json.getInt(CONNECTION_STATUS);
if (success == 1)
// products found
// Getting Array of Products
Events = json.getJSONArray(TABLE_EVENT);
// looping through All Contacts
for (int i = 0; i < Events.length(); i++)
JSONObject evt = Events.getJSONObject(i);
// Storing each json item in variable
id = evt.getString(pid);
group = evt.getString(COL_GROUP);
name = evt.getString(COL_NAME);
desc = evt.getString(COL_DESC);
date = evt.getString(COL_DATE);
time = evt.getString(COL_TIME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(pid, id);
map.put(COL_GROUP, group);
map.put(COL_NAME, name);
map.put(COL_DESC, desc);
map.put(COL_DATE, date);
map.put(COL_TIME, time);
// adding HashList to ArrayList
eventsList.add(map);
else
// Options are not available or server is down.
// Dismiss the loading dialog and display an alert
// onPostExecute
pDialog.dismiss();
catch (JSONException e)
e.printStackTrace();
return null;
protected void onPostExecute(String file_url)
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
getActivity().runOnUiThread(new Runnable()
public void run()
ListAdapter adapter = new SimpleAdapter(getActivity(),
eventsList, R.layout.list_item, new String[]
pid, COL_GROUP, COL_NAME, COL_DATE, COL_TIME ,
new int[] R.id.pid, R.id.group, R.id.name, R.id.header,
R.id.title2 );
setListAdapter(adapter);
);
活动详情类：
public class EventDetails extends Activity
String pid;
TextView EvtName, EvtDesc, EvtDate, EvtTime, Header;
ImageView logo;
private String url_event_details = "http://centrubook.eu.pn/eventDetails.php";
private ProgressDialog pDialog;
JSONParser jParser = new JSONParser();
// JSON Node names
private static final String CONNECTION_STATUS = "success";
private static final String TABLE_EVENT = "Event";
private static final String COL_PID = "pid";
private static final String COL_NAME = "Event_Name";
private static final String COL_DESC = "Event_Desc";
private static final String COL_DATE = "Event_Date";
private static final String COL_TIME = "Event_Time";
@Override
public boolean onOptionsItemSelected(MenuItem item)
switch (item.getItemId())
// Respond to the action bar's Up/Home button
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
return super.onOptionsItemSelected(item);
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.eventdetails);
// ActionBar actionBar = getActionBar();
// actionBar.setDisplayHomeAsUpEnabled(true);
EvtName = (TextView) findViewById(R.id.BombaName);
EvtDesc = (TextView) findViewById(R.id.BombaDesc);
EvtDate = (TextView) findViewById(R.id.BombaDate);
EvtTime = (TextView) findViewById(R.id.BombaTime);
logo = (ImageView) findViewById(R.id.BombaLogo);
Intent i = getIntent();
pid = i.getStringExtra(COL_PID);
new getEventDetails().execute();
class getEventDetails extends AsyncTask<String, String, String>
String name, desc, date, time;
@Override
protected void onPreExecute()
super.onPreExecute();
pDialog = new ProgressDialog(EventDetails.this);
pDialog.setMessage("Just a moment...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
@Override
protected String doInBackground(String... args)
// Check for success tag
int success;
try
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pid", pid));
// getting product details by making HTTP request
// Note that product details url will use GET request
JSONObject json = jParser.makeHttpRequest(url_event_details,
"GET", params);
// json success tag
success = json.getInt(CONNECTION_STATUS);
if (success == 1)
// successfully received product details
JSONArray eventsObj = json.getJSONArray(TABLE_EVENT);
// get first product object from JSON Array
JSONObject details = eventsObj.getJSONObject(0);
name = details.getString(COL_NAME);
desc = details.getString(COL_DESC);
date = details.getString(COL_DATE);
time = details.getString(COL_TIME);
else
// product with pid not found
catch (JSONException e)
e.printStackTrace();
return null;
protected void onPostExecute(final String file_url)
pDialog.dismiss();
runOnUiThread(new Runnable()
public void run()
EvtName.setText(name);
EvtDesc.setText(desc);
EvtDate.setText(date);
EvtTime.setText(time);
logo.setImageResource(R.drawable.events);
);
希望这会有所帮助；）
【讨论】：
嗨@user788971，如果它对你有帮助，你能接受这个答案吗？ 谢谢，HttpClient 自您的帖子以来已被弃用，更新的课程可以在这里找到：danielnugent.blogspot.com.by/2015/06/… 显然现在你会使用 Volley 来处理这个请求【参考方案5】：我做了一个这样的简单 JSONAdapter：
public abstract class JSONAdapter extends BaseAdapter
private JSONArray array;
@Override
public int getCount()
return array == null ? 0 : array.length();
@Override
public Object getItem(final int position)
if (array == null | array.length() < position)
return null;
try
return array.get(position);
catch (final JSONException e)
e.printStackTrace();
return null;
@Override
public long getItemId(final int position)
return position;
public JSONObject getObject(final int position)
return (JSONObject) getItem(position);
public void setData(final JSONArray data)
array = data;
notifyDataSetChanged();
然后当我需要它的特定实例时，我必须根据我的具体需要覆盖适配器中的 getView 方法：
@Override
public View getView(final int position, final View convertView,
final ViewGroup parent)
final View view;
final ViewHolder holder;
if (convertView != null)
view = convertView;
holder = (ViewHolder) view.getTag();
else
view = context.getLayoutInflater().inflate(
R.layout.<mylayout>, parent, false);
holder = new ViewHolder();
holder.name = (TextView) view.findViewById(R.id.name);
[...]
view.setTag(holder);
final JSONObject jsonObj = getObject(position);
holder.name.setText(jsonObj.optString("name"));
[...]
return view;
并像这样设置数据：
final JSONObject json = new JSONObject(jsonString);
adapter.setData(json.getJSONArray("projects"));
【讨论】：
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