我正在开发一个从 Web 服务解析 JSON 数据的应用程序。然后将此数据存储在列表视图中，我正在尝试启用应用程序以允许我单击列表中的项目。反过来，通过单击我试图将活动从列表视图切换到 Web 视图的项目。但是，当我单击列表中的任何项目时，应用程序指出发生了异常，显示一条消息，指出“不幸的是 [应用程序名称] 已停止。”，然后退出应用程序。
除了这个之外，应用程序中没有其他问题。因此，如果有人可以帮助我解决此问题，我将不胜感激。我提供了主要活动的全部代码，问题发生在 onCreate 的 try catch 中，您也可以从这里下载应用程序：http: //bit.ly/17rePw0
public class MainActivity extends ListActivity
{
GPSManager gpsManager;
ConnectionManager connectManager;
LocationManager locationManager = null;
LocationListener locationListener = null;
AlertDialogManager alertManager = new AlertDialogManager();
private ProgressDialog progDialog;
JSONParser parser = new JSONParser();
ArrayList<HashMap<String, String>> articleList;
private String URL_ARTICLES = "http://api.wikilocation.org/articles?lat=56.4607208&lng=-2.9680668&format=json&radius=100";
private static final String TAG_ARTICLES = "articles";
private static final String TAG_ID = "id";
private static final String TAG_LAT = "lat";
private static final String TAG_LNG = "lng";
private static final String TAG_NAME = "title";
private static final String TAG_URL = "url";
private static final String TAG_DISTANCE = "distance";
private static final int ARTICLE_LIMIT = 20;
private static int ARTICLE_RADIUS = 100;
JSONArray articles = null;
double lat, lng;
String latitude, longitude;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
articleList = new ArrayList<HashMap<String, String>>();
connectManager = new ConnectionManager(getApplicationContext());
gpsManager = new GPSManager(this);
if(gpsManager.RetrieveLocation)
{
lat = gpsManager.RetrieveLatitude();
lng = gpsManager.RetrieveLongitude();
latitude = String.valueOf(lat);
longitude = String.valueOf(lng);
//URL_ARTICLES = "http://api.wikilocation.org/articles?lat=" + latitude + "&lng=" + longitude + "&format=json&radius=100";
}
else
{
gpsManager.showSettingsAlert();
}
new LoadArticles().execute();
ListView listView = getListView();
try
{
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapt, View view, int position, long id) {
Intent intent = new Intent(MainActivity.this, WebActivity.class);
startActivity(intent);
}
});
}
catch(Exception e)
{
e.printStackTrace();
}
}
class LoadArticles extends AsyncTask<String, String, String>
{
protected void onPreExecute()
{
super.onPreExecute();
progDialog = new ProgressDialog(MainActivity.this);
progDialog.setMessage("Loading Articles");
progDialog.setIndeterminate(false);
progDialog.setCancelable(false);
progDialog.show();
}
protected String doInBackground(String... args)
{
List<NameValuePair>params = new ArrayList<NameValuePair>();
String json = parser.makeHttpRequest(URL_ARTICLES, "GET", params);
Log.d("Articles JSON: ", "> " + json);
try
{
JSONObject jObj = new JSONObject(json);
if(jObj != null)
{
articles = jObj.getJSONArray(TAG_ARTICLES);
for(int i = 0; i < articles.length(); i++)
{
JSONObject obj = articles.getJSONObject(i);
String id = obj.getString(TAG_ID);
String lat = obj.getString(TAG_LAT);
String lng = obj.getString(TAG_LNG);
String name = obj.getString(TAG_NAME);
String address = obj.getString(TAG_URL);
String distance = obj.getString(TAG_DISTANCE);
HashMap<String, String>map = new HashMap<String, String>();
map.put(TAG_ID, id);
map.put(TAG_LAT, lat);
map.put(TAG_LNG, lng);
map.put(TAG_NAME, name);
map.put(TAG_URL, address);
map.put(TAG_DISTANCE, distance);
articleList.add(map);
}
}
}
catch(JSONException e)
{
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url)
{
progDialog.dismiss();
runOnUiThread(new Runnable(){
public void run()
{
ListAdapter adapter = new SimpleAdapter(MainActivity.this, articleList,
R.layout.list_item_articles, new String[]
{
TAG_ID, TAG_NAME, TAG_DISTANCE }, new int[]{ R.id.artcile_id, R.id.article_name, R.id.article_distance
});
setListAdapter(adapter);
}
});
}
}
}
编辑：添加了 LogCat 堆栈跟踪。
08-03 23:44:02.407: W/dalvikvm(875): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
08-03 23:44:02.457: E/AndroidRuntime(875): FATAL EXCEPTION: main
08-03 23:44:02.457: E/AndroidRuntime(875): android.content.ActivityNotFoundException: Unable to find explicit activity class {com.android.muc2013/com.android.muc2013.WebActivity}; have you declared this activity in your AndroidManifest.xml?
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1618)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1417)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Activity.startActivityForResult(Activity.java:3370)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Activity.startActivityForResult(Activity.java:3331)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Activity.startActivity(Activity.java:3566)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.Activity.startActivity(Activity.java:3534)
08-03 23:44:02.457: E/AndroidRuntime(875): at com.android.muc2013.MainActivity$1.onItemClick(MainActivity.java:99)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.widget.AdapterView.performItemClick(AdapterView.java:298)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2749)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.widget.AbsListView$1.run(AbsListView.java:3423)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.os.Handler.handleCallback(Handler.java:725)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.os.Handler.dispatchMessage(Handler.java:92)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.os.Looper.loop(Looper.java:137)
08-03 23:44:02.457: E/AndroidRuntime(875): at android.app.ActivityThread.main(ActivityThread.java:5041)
08-03 23:44:02.457: E/AndroidRuntime(875): at java.lang.reflect.Method.invokeNative(Native Method)
08-03 23:44:02.457: E/AndroidRuntime(875): at java.lang.reflect.Method.invoke(Method.java:511)
08-03 23:44:02.457: E/AndroidRuntime(875): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-03 23:44:02.457: E/AndroidRuntime(875): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-03 23:44:02.457: E/AndroidRuntime(875): at dalvik.system.NativeStart.main(Native Method)