Android ListView中的数据库错误：应用程序已停止

我有一个ListView，其中我从Android中的MySQL数据库加载所有项目，并显示这些项目。由于列表需要更新，在活动中，我使用Asynctask函数每隔15秒刷新一次列表，并更新ListView。还有一个滚动条，因为可能有很多项目，这里是错误发生的地方。如果我通过滚动条向上或向下移动，它运行良好。但是，如果我正在使用滚动条，同时活动尝试访问数据库以加载更新的项目，则应用程序将停止

以下是日志：

   06-23 15:36:32.867: E/AndroidRuntime(7788): FATAL EXCEPTION: main
    06-23 15:36:32.867: E/AndroidRuntime(7788): java.lang.IndexOutOfBoundsException: Invalid index 14, size is 0
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:251)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at java.util.ArrayList.get(ArrayList.java:304)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.SimpleAdapter.bindView(SimpleAdapter.java:147)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.SimpleAdapter.createViewFromResource(SimpleAdapter.java:126)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.SimpleAdapter.getView(SimpleAdapter.java:114)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.AbsListView.obtainView(AbsListView.java:2445)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.ListView.makeAndAddView(ListView.java:1769)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.ListView.fillUp(ListView.java:706)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.ListView.fillGap(ListView.java:645)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.AbsListView.trackMotionScroll(AbsListView.java:5530)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.AbsListView.scrollIfNeeded(AbsListView.java:3509)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.widget.AbsListView.onTouchEvent(AbsListView.java:3906)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.View.dispatchTouchEvent(View.java:7340)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2179)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1914)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1928)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1928)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1928)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1928)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1928)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2113)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1466)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.app.Activity.dispatchTouchEvent(Activity.java:2468)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2061)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.View.dispatchPointerEvent(View.java:7525)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3368)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3300)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4392)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4370)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4474)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:163)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:4442)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:4493)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.Choreographer.doCallbacks(Choreographer.java:555)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.Choreographer.doFrame(Choreographer.java:523)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.os.Handler.handleCallback(Handler.java:615)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.os.Handler.dispatchMessage(Handler.java:92)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.os.Looper.loop(Looper.java:137)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at android.app.ActivityThread.main(ActivityThread.java:4895)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at java.lang.reflect.Method.invokeNative(Native Method)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at java.lang.reflect.Method.invoke(Method.java:511)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
    06-23 15:36:32.867: E/AndroidRuntime(7788):     at dalvik.system.NativeStart.main(Native Method)

谢谢你的帮助

编辑：下面是我用来每隔15秒刷新Listview的代码： @凌驾

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.all_candidatos);
        StrictMode.ThreadPolicy policy = new StrictMode. ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy);

        boolean isReachable = false;
        try{
            isReachable = InetAddress.getByName("192.168.1.41").isReachable(200);
        } catch (Exception e){
            Log.e("InetAddress", e.getMessage());




        }finally {
            if (isReachable) {

                new CargarCandidatos().execute();
        timer();


            }else{
                Toast.makeText(getApplicationContext(), R.string.errorserver, Toast.LENGTH_LONG).show();
            }

        }
        setListAdapter(adapter);

        candidatosList = new ArrayList<HashMap<String, String>>();



    }
//
//  
    public void timer(){
         new CountDownTimer(tiempo, 1000) {

                public void onTick(long millisUntilFinished) {

                }

                public void onFinish() {
                    candidatosList.clear();
                    new CargarCandidatos().execute();


                    timer();

                }
             }.start();}




    class CargarCandidatos extends AsyncTask<String, Void, String> {


        @Override
        protected void onPreExecute() {
            if(!isFinishing()){
            super.onPreExecute();
            pDialog = new ProgressDialog(Monitorizacion.this);
            pDialog.setMessage("Monitorizando ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }
        }


        protected String doInBackground(String... args) {




                try {
                    monitorizar();
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();}
                return null;




        }


        protected void onPostExecute(String file_url) {
    pDialog.dismiss();
            runOnUiThread(new Runnable() {
                public void run() {

                    adapter = new SimpleAdapter(
                            Monitorizacion.this, candidatosList,
                            R.layout.list_item, new String[] { TAG_NSERIE,
                                    TAG_DNI, TAG_NOMBRE, TAG_TEST, TAG_PREGUNTA, TAG_BATERIA,TAG_CORRECTAS, TAG_ERRORES},
                            new int[] { R.id.id, R.id.dni, R.id.nombre, R.id.test, R.id.pregunta, R.id.bateria, R.id.correctas, R.id.fallos});

                    adapter.notifyDataSetChanged();
                    setListAdapter(adapter);


                }
            });

        }

    }
    public void monitorizar() throws Exception{
        try {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            JSONObject json = jParser.makeHttpRequest(url_candidatos, "GET", params);
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                candidatos = json.getJSONArray(TAG_CANDIDATOS);

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

                    String nserie = c.getString(TAG_NSERIE);
                    String dni = c.getString(TAG_DNI);
                    String nombre = c.getString(TAG_NOMBRE);
                    String test = c.getString(TAG_TEST);
                    String pregunta = c.getString(TAG_PREGUNTA);
                    String bateria = c.getString(TAG_BATERIA);
                    String correctas = c.getString(TAG_CORRECTAS);
                    String errores = c.getString(TAG_ERRORES);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_NSERIE, nserie);
                    map.put(TAG_DNI, dni);
                    map.put(TAG_NOMBRE, nombre);
                    map.put(TAG_TEST, test);
                    map.put(TAG_PREGUNTA, pregunta);
                    map.put(TAG_BATERIA, bateria);
                    map.put(TAG_CORRECTAS, correctas);
                    map.put(TAG_ERRORES, errores);
                    candidatosList.add(map);
                }
            } 
        } catch (JSONException e) {
            e.printStackTrace();
        }



    }
}

public void onCreate（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（右布局，所有候选对象）；
StrictMode.ThreadPolicy policy=新建StrictMode.ThreadPolicy.Builder（）.permitAll（）.build（）；StrictMode.setThreadPolicy（策略）；
布尔值isReachable=false；
试一试{
isReachable=InetAddress.getByName（“192.168.1.41”）。isReachable（200）；
}捕获（例外e）{
Log.e（“InetAddress”，e.getMessage（））；
}最后{
如果（isReachable）{
新的CargarCandidatos（）.execute（）；
定时器（）；
}否则{
Toast.makeText（getApplicationContext（），R.string.errorserver，Toast.LENGTH\u LONG.show（）；
}
}
setListAdapter（适配器）；
CandidatesList=新的ArrayList（）；
}
//
//  
公共无效计时器（）{
新的倒计时器（tiempo，1000）{
公共void onTick（长毫秒未完成）{
}
公共无效onFinish（）{
candidateList.clear（）；
新的CargarCandidatos（）.execute（）；
定时器（）；
}
}.start（）；}
类CargarCandidatos扩展了异步任务{
@凌驾
受保护的void onPreExecute（）{
如果（！isFinishing（））{
super.onPreExecute（）；
pDialog=新建进度对话框（Monitorizacion.this）；
setMessage（“Monitorizando…”）；
pDialog.setUndeterminate（假）；
pDialog.setCancelable（假）；
pDialog.show（）；
}
}
受保护的字符串doInBackground（字符串…args）{
试一试{
monitorizar（）；
}捕获（例外e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；}
返回null；
}
受保护的void onPostExecute（字符串文件\u url）{
pDialog.disclose（）；
runOnUiThread（新的Runnable（）{
公开募捐{
适配器=新的SimpleAdapter(
这个，候选人名单，
R.layout.list_项，新字符串[]{TAG_NSERIE，
标记DNI、标记NOMBRE、标记TEST、标记PREGUNTA、标记BATERIA、标记CORPORTAS、标记ERRORS}，
新int[]{R.id.id，R.id.dni，R.id.nombre，R.id.test，R.id.pregunta，R.id.bateria，R.id.correctas，R.id.fallos}）；
adapter.notifyDataSetChanged（）；
setListAdapter（适配器）；
}
});
}
}
public void monitorizar（）引发异常{
试一试{
List params=new ArrayList（）；
JSONObject json=jParser.makeHttpRequest（url_candidates，“GET”，params）；
int success=json.getInt（TAG_success）；
如果（成功==1）{
candidateos=json.getJSONArray（TAG_candidateos）；
对于（int i=0；i

编辑： 问题是，如果我向上或向下滚动Listview，此时调用asynctask函数访问数据库，则会发生错误，应用程序停止

Michael Butscher解决方案： 根据我的理解，我用迈克尔·布彻的建议解决了这个问题：

    public void timer(){
         new CountDownTimer(tiempo, 1000) {

                public void onTick(long millisUntilFinished) {

                }

                public void onFinish() {
                    new CargarCandidatos().execute();


                    timer();

                }
             }.start();}




    class CargarCandidatos extends AsyncTask<String, Void, String> {


        @Override
        protected void onPreExecute() {
            if(!isFinishing()){
            super.onPreExecute();
            pDialog = new ProgressDialog(Monitorizacion.this);
            pDialog.setMessage("Monitorizando ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }
        }


        protected String doInBackground(String... args) {




                try {
                    monitorizar();
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();}
                return null;




        }


        protected void onPostExecute(String file_url) {
    pDialog.dismiss();
            runOnUiThread(new Runnable() {
                public void run() {

                    adapter = new SimpleAdapter(
                            Monitorizacion.this, candidatosList,
                            R.layout.list_item, new String[] { TAG_NSERIE,
                                    TAG_DNI, TAG_NOMBRE, TAG_TEST, TAG_PREGUNTA, TAG_BATERIA,TAG_CORRECTAS, TAG_ERRORES},
                            new int[] { R.id.id, R.id.dni, R.id.nombre, R.id.test, R.id.pregunta, R.id.bateria, R.id.correctas, R.id.fallos});

                    adapter.notifyDataSetChanged();
                    setListAdapter(adapter);



                }
            });

        }

    }
    public void monitorizar() throws Exception{
        try {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            JSONObject json = jParser.makeHttpRequest(url_candidatos, "GET", params);
            ArrayList<HashMap<String, String>> temp;
            temp = new ArrayList<HashMap<String, String>>();


            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                candidatos = json.getJSONArray(TAG_CANDIDATOS);

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

                    String nserie = c.getString(TAG_NSERIE);
                    String dni = c.getString(TAG_DNI);
                    String nombre = c.getString(TAG_NOMBRE);
                    String test = c.getString(TAG_TEST);
                    String pregunta = c.getString(TAG_PREGUNTA);
                    String bateria = c.getString(TAG_BATERIA);
                    String correctas = c.getString(TAG_CORRECTAS);
                    String errores = c.getString(TAG_ERRORES);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_NSERIE, nserie);
                    map.put(TAG_DNI, dni);
                    map.put(TAG_NOMBRE, nombre);
                    map.put(TAG_TEST, test);
                    map.put(TAG_PREGUNTA, pregunta);
                    map.put(TAG_BATERIA, bateria);
                    map.put(TAG_CORRECTAS, correctas);
                    map.put(TAG_ERRORES, errores);
                    temp.add(map);
                    candidatosList = temp;
                }
            } 
        } catch (JSONException e) {
            e.printStackTrace();
        }



    }
}

公共无效计时器（）{
新的倒计时器（tiempo，1000）{
公共void onTick（长毫秒未完成）{
}
公共无效onFinish（）{
新的CargarCandidatos（）.execute（）；
定时器（）；
}
}.start（）；}
类CargarCandidatos扩展了异步任务{
@凌驾
受保护的void onPreExecute（）{
如果（！isFinishing（））{
super.onPreExecute（）；
pDialog=新建进度对话框（Monitorizacion.this）；
setMessage（“Monitorizando…”）；
pDialog.setUndeterminate（假）；
pDialog.se