从列表视图启动活动时出错

时间:2013-08-07 05:01:27

标签: android json listview

我正在尝试从列表视图中启动一个活动,但有一些错误

  • 我可以填充JSON数据,但是当我点击该行时 列表(用于启动活动)我收到错误
  • 我已经提到了
  • 下面的logcat输出

任何想法?


CopperChimney.java

public class CopperChimney extends Activity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.copperchimney_desc_screen);

        Button btn1=(Button) findViewById(R.id.TopBackButton);

        btn1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent emp1=new Intent(CopperChimney.this,MainActivity.class);
                startActivity(emp1);
            }
        }); 
    }
}

MainActivity.java

public class MainActivity extends Activity {

    // url to make request
    private static String url = "http://54.218.73.244:7000/";
    List<Item> yourData = new ArrayList<Item>();

    ProgressDialog progressDialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Instantiating ProgressDialog with onCreate method
        progressDialog=new ProgressDialog(MainActivity.this);
        new ParsingAsync().execute();

    }

    private class ParsingAsync extends AsyncTask<Void, Void, Void>
    {

        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            super.onPreExecute();
            progressDialog=ProgressDialog.show(MainActivity.this, "", "Please Wait", true, false);


        }

        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub

            // Creating JSON Parser instance
            JSONParser jParser = new JSONParser();

            // getting JSON string from URL
            JSONArray json = jParser.getJSONFromUrl(url);

            try {
                for (int i = 0; i < json.length(); i++) {
                    JSONObject c = json.getJSONObject(i);

                    // Storing each json item in variable
                    String NAME=c.getString("restaurantNAME");

                    yourData.add(new Item(NAME));
                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            return null;
        }


        @Override
        protected void onPostExecute(Void result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            progressDialog.dismiss();

            ListView yourListView = (ListView) findViewById(R.id.listViewID);
            ListAdapter customAdapter = new ListAdapter(MainActivity.this, R.layout.itemlistrow, yourData);
            yourListView.setAdapter(customAdapter);
            yourListView.setOnItemClickListener(new OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {
                    // When clicked, show a toast with the TextView text
                    if(position == 0)
                    {
                        //code specific to first list item    
                        Intent myIntent = new Intent(MainActivity.this,CopperChimney.class);
                        startActivity(myIntent);
                    }

                }
            });

        }

    }

}

清单

   <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".CopperChimney"
            android:label="@string/app_name" >
        </activity>

    </application>

logcat的

08-07 09:05:30.062: E/Buffer Error(408): Error converting result java.lang.NullPointerException
08-07 09:05:30.091: E/JSON Parser(408): Error parsing data org.json.JSONException: End of input at character 0 of 
08-07 09:05:30.091: W/dalvikvm(408): threadid=9: thread exiting with uncaught exception (group=0x40015560)
08-07 09:05:30.111: E/AndroidRuntime(408): FATAL EXCEPTION: AsyncTask #1
08-07 09:05:30.111: E/AndroidRuntime(408): java.lang.RuntimeException: An error occured while executing doInBackground()
08-07 09:05:30.111: E/AndroidRuntime(408):  at android.os.AsyncTask$3.done(AsyncTask.java:200)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.FutureTask.run(FutureTask.java:138)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.lang.Thread.run(Thread.java:1019)
08-07 09:05:30.111: E/AndroidRuntime(408): Caused by: java.lang.NullPointerException
08-07 09:05:30.111: E/AndroidRuntime(408):  at com.MAIN_REF.findmybuffet.MainActivity$ParsingAsync.doInBackground(MainActivity.java:71)
08-07 09:05:30.111: E/AndroidRuntime(408):  at com.MAIN_REF.findmybuffet.MainActivity$ParsingAsync.doInBackground(MainActivity.java:1)
08-07 09:05:30.111: E/AndroidRuntime(408):  at android.os.AsyncTask$2.call(AsyncTask.java:185)
08-07 09:05:30.111: E/AndroidRuntime(408):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
08-07 09:05:30.111: E/AndroidRuntime(408):  ... 4 more
08-07 09:05:32.721: E/WindowManager(408): Activity com.MAIN_REF.findmybuffet.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40521200 that was originally added here
08-07 09:05:32.721: E/WindowManager(408): android.view.WindowLeaked: Activity com.MAIN_REF.findmybuffet.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40521200 that was originally added here
08-07 09:05:32.721: E/WindowManager(408):   at android.view.ViewRoot.<init>(ViewRoot.java:258)
08-07 09:05:32.721: E/WindowManager(408):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
08-07 09:05:32.721: E/WindowManager(408):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
08-07 09:05:32.721: E/WindowManager(408):   at android.view.Window$LocalWindowManager.addView(Window.java:424)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.Dialog.show(Dialog.java:241)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ProgressDialog.show(ProgressDialog.java:107)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ProgressDialog.show(ProgressDialog.java:95)
08-07 09:05:32.721: E/WindowManager(408):   at com.MAIN_REF.findmybuffet.MainActivity$ParsingAsync.onPreExecute(MainActivity.java:55)
08-07 09:05:32.721: E/WindowManager(408):   at android.os.AsyncTask.execute(AsyncTask.java:391)
08-07 09:05:32.721: E/WindowManager(408):   at com.MAIN_REF.findmybuffet.MainActivity.onCreate(MainActivity.java:42)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-07 09:05:32.721: E/WindowManager(408):   at android.os.Handler.dispatchMessage(Handler.java:99)
08-07 09:05:32.721: E/WindowManager(408):   at android.os.Looper.loop(Looper.java:123)
08-07 09:05:32.721: E/WindowManager(408):   at android.app.ActivityThread.main(ActivityThread.java:3683)
08-07 09:05:32.721: E/WindowManager(408):   at java.lang.reflect.Method.invokeNative(Native Method)
08-07 09:05:32.721: E/WindowManager(408):   at java.lang.reflect.Method.invoke(Method.java:507)
08-07 09:05:32.721: E/WindowManager(408):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-07 09:05:32.721: E/WindowManager(408):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-07 09:05:32.721: E/WindowManager(408):   at dalvik.system.NativeStart.main(Native Method)

谢谢,

0 个答案:

没有答案