我对 Android 开发还是很陌生,正在做一个应用程序/项目,其中涉及将这个 JSON(下面列出)加载到一个ListView
带有名称、描述和图像的文件中,但它在模拟器上一直是空白的。请告诉我我做错了什么 - 任何帮助将不胜感激!(越具体越好,因为我是新手..)
JSON:
{
"success":true,
"games":[
{
"id":"1",
"name":"Name of the Game",
"description":"This is what it is about",
"image":"IMAGE URL"
}
]
}
AndroidJSONParsingActivity:
// URL to make request
private static final String url = "URL of API";
// JSON Node names
private static final String TAG_GAMES = "games";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_DESCRIPTION = "description";
private static final String TAG_IMAGE = "image";
// games JSONArray
JSONArray games = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Hash map for ListView
ArrayList<HashMap<String, String>> gameList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Games
games = json.getJSONArray(TAG_GAMES);
// looping through All Games
for(int i = 0; i < games.length(); i++){
JSONObject c = games.getJSONObject(i);
// Storing each JSON item in variable
String id = c.getString(TAG_ID);
String image = c.getString(TAG_IMAGE);
// is again JSON Object
JSONObject author = c.getJSONObject(TAG_DESCRIPTION);
String name = author.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put( TAG_IMAGE, image);
// adding HashList to ArrayList
gameList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, gameList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_DESCRIPTION }, new int[] {
R.id.name, R.id.description });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String description = ((TextView) view.findViewById(R.id.description)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_DESCRIPTION, description);
startActivity(in);
}
});
}
JSON解析器:
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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;
}
}
主.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView
Always give id value as list(@android:id/list)
-->
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
list_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<!-- Name Label -->
<TextView
android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#43bd00"
android:textSize="16sp"
android:textStyle="bold"
android:paddingTop="6dip"
android:paddingBottom="2dip" />
<TextView
android:id="@+id/description"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#acacac"
android:paddingBottom="2dip" />
</LinearLayout>
添加 LogCat 信息:
01-03 06:16:15.254: E/ActivityThread(616): Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.254: E/ActivityThread(616): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.254: E/ActivityThread(616): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
01-03 06:16:15.254: E/ActivityThread(616): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
01-03 06:16:15.254: E/ActivityThread(616): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
01-03 06:16:15.254: E/ActivityThread(616): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
01-03 06:16:15.254: E/ActivityThread(616): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
01-03 06:16:15.254: E/ActivityThread(616): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
01-03 06:16:15.254: E/ActivityThread(616): at android.os.AsyncTask$2.call(AsyncTask.java:287)
01-03 06:16:15.254: E/ActivityThread(616): at java.util.concurrent.FutureTask.run(FutureTask.java:234)
01-03 06:16:15.254: E/ActivityThread(616): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
01-03 06:16:15.254: E/ActivityThread(616): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
01-03 06:16:15.254: E/ActivityThread(616): at java.lang.Thread.run(Thread.java:856)
01-03 06:16:15.365: E/StrictMode(616): null
01-03 06:16:15.365: E/StrictMode(616): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.365: E/StrictMode(616): at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
01-03 06:16:15.365: E/StrictMode(616): at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
01-03 06:16:15.365: E/StrictMode(616): at android.app.ContextImpl.bindService(ContextImpl.java:1418)
01-03 06:16:15.365: E/StrictMode(616): at android.app.ContextImpl.bindService(ContextImpl.java:1407)
01-03 06:16:15.365: E/StrictMode(616): at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
01-03 06:16:15.365: E/StrictMode(616): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
01-03 06:16:15.365: E/StrictMode(616): at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
01-03 06:16:15.365: E/StrictMode(616): at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
01-03 06:16:15.365: E/StrictMode(616): at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
01-03 06:16:15.365: E/StrictMode(616): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
01-03 06:16:15.365: E/StrictMode(616): at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
01-03 06:16:15.365: E/StrictMode(616): at android.os.AsyncTask$2.call(AsyncTask.java:287)