Android应用程序中的listview中的奇怪故障

我的应用程序中有两个奇怪的故障

1. 使用Listview时，当我快速向下和向上滚动时，第一个项目会更改。

我没有实现任何可能导致此问题的方法，Listview是否有故障？

2. 更新Listview时，它会获取数据，然后更新它时，它会正确执行前12个项目，然后再次重复它们，然后再次重复前6个项目（对于宿舍总数），我找不到它在12点重复的原因特别是这是我的代码

MainActivity类：

public class MainActivity extends AppCompatActivity {

private Button btnGetData;
private final String URL = "https://www.laundryalert.com/cgi-bin/urba7723/LMPage?Login=True";

private List<DormMachines> dorms;
private BaseAdapterDorm dormsAdapter;
private ListView dormsList;

private ProgressDialog mProgressDialog;

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

    // Set click listener for button
    btnGetData = (Button) findViewById(R.id.btnContent);
    btnGetData.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new GetContent().execute();

        }
    });         dorms = new ArrayList<DormMachines>();

    dormsList = (ListView) findViewById(R.id.myListView);
    dormsAdapter = new BaseAdapterDorm(dorms, this);

    dormsList.setAdapter(dormsAdapter);

    setupListViewListener();
}

private void setupListViewListener() {
    dormsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            dorms.remove(position);
            dormsAdapter.notifyDataSetChanged();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return true;
}

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

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog = new ProgressDialog(MainActivity.this);
        mProgressDialog.setTitle("Getting Content");
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        dorms.clear();

        try {
            Document doc = Jsoup.connect(URL).get();
            Element table = doc.getElementById("tableb");
            Elements rows = table.getElementsByTag("tr");

            // Removes table headers and whitespace at end
            rows.remove(0);
            rows.remove(0);
            rows.remove(30);

            for(Element row : rows) {
                int index = 0;
                DormMachines dorm = new DormMachines();
                for (Element rowData : row.getElementsByTag("td")) {
                    switch (index) {
                        case 1:
                            // Dorm Name
                            dorm.dormName = rowData.text();
                            break;
                        case 2:
                            // Washers Free
                            dorm.washersFree = Integer.parseInt(rowData.text());
                            break;
                        case 3:
                            // Dryers Free
                            dorm.dryersFree = Integer.parseInt(rowData.text());
                            break;
                        case 5:
                            // Washers in Use
                            dorm.washersInUse = Integer.parseInt(rowData.text());
                            break;
                        case 7:
                            // Dryers In Use
                            dorm.dryersInUse = Integer.parseInt(rowData.text());
                            break;
                        default:
                            break;

                    }
                    index++;
                }
                dorms.add(dorm);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        dormsAdapter.notifyDataSetChanged();
        mProgressDialog.dismiss();
    }
}

}

BaseAdapterDorm类：

public class BaseAdapterDorm extends BaseAdapter {    
private List<DormMachines> list;
private LayoutInflater layoutInflater;

public BaseAdapterDorm(List<DormMachines> list, Context context) {
    this.list = list;
    this.layoutInflater =(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return list.size();
}

@Override
public Object getItem(int position) {
    return list.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View view, ViewGroup parent) {
    DormViewHolder dormViewHolder;

    if(view == null) {
        view = layoutInflater.inflate(R.layout.listview_dorm_item, parent, false);

        dormViewHolder = new DormViewHolder();

        dormViewHolder.textViewDormName = (TextView) view.findViewById(R.id.list_item_dorm_item_name);
        dormViewHolder.textViewWasherAvail = (TextView) view.findViewById(R.id.list_item_washers_avail);
        dormViewHolder.textViewWasherOccupied = (TextView) view.findViewById(R.id.list_item_washer_occupied);
        dormViewHolder.textViewDryersAvail = (TextView) view.findViewById(R.id.list_item_dryers_avail);
        dormViewHolder.textViewDryersOccupied = (TextView) view.findViewById(R.id.list_item_dryers_occupied);

        dormViewHolder.textViewDormName.setText(list.get(position).dormName);
        dormViewHolder.textViewWasherAvail.setText(""+list.get(position).washersFree);
        dormViewHolder.textViewWasherOccupied.setText(""+list.get(position).washersInUse);
        dormViewHolder.textViewDryersAvail.setText(""+list.get(position).dryersFree);
        dormViewHolder.textViewDryersOccupied.setText(""+list.get(position).dryersInUse);
    }
    return view;
}

static class DormViewHolder {
    TextView textViewDormName;
    TextView textViewWasherAvail;
    TextView textViewWasherOccupied;
    TextView textViewDryersAvail;
    TextView textViewDryersOccupied;
}

}

布局：

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="8sp"
    tools:context="com.sergiodlz.jsoupexample.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">


        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Get data"
            android:id="@+id/btnContent"/>

    </LinearLayout>

    <ListView
        android:layout_width="match_parent"
        android:layout_height="0sp"
        android:id="@+id/myListView"
        android:layout_weight="1">

    </ListView>


</LinearLayout>

其余的在Github上