Question

（抱歉，我不擅长英语）我创建了一个自定义BaseAdapter来将我的数据从sqlite显示到ListView。现在我可以看到列表但是当我快速滚动列表视图时，行奇怪地查看。我无法理解这一点。还有一个奇怪的地方是，如果我有5个数据行，getView运行5次，但只能显示前4行。我使用日志，我看到5次“返回视图”;清楚。

以下是我的适配器代码：

public class LocalRankAdapter extends BaseAdapter {
private static final String FIELD1 = "time";
private static final String FIELD2 = "name";
private static final String TABLE_NAME = "rank";
private static final String FIELD_ORDER = "time";

private DataBaseHelper dbHelper;
private Cursor mCursor;
private Context mContext;
private int timeColIndex;
private int nameColIndex;
private int index;
private int length;
public static float recent_time=0;
public static String recent_playerName="";

public LocalRankAdapter(Context context, DataBaseHelper mdbHelper) {
    mContext=context;
    dbHelper=mdbHelper;

    // get data from database
    mCursor = dbHelper.getData(TABLE_NAME, new String[] { FIELD1, FIELD2 }, FIELD1 + " !=0 ", FIELD_ORDER + " ASC");
    mCursor.moveToFirst();
    length=mCursor.getCount();

    timeColIndex=mCursor.getColumnIndex(FIELD1);
    nameColIndex=mCursor.getColumnIndex(FIELD2);

    index=1;
}

public static void insertData(DataBaseHelper dbHelper, float currentTime, String name) {
    ContentValues cv=new ContentValues();
    cv.put(FIELD1, currentTime);
    cv.put(FIELD2, name);
    dbHelper.insertData(TABLE_NAME, new String[] {FIELD1, FIELD2}, cv);
}

@Override
public int getCount() {
    return length-1;
}

@Override
public View getView(int id, View convertView, ViewGroup parent) { 
    View v=convertView;
    if (convertView == null) {
        v=convertView;
        LayoutInflater inflater = (LayoutInflater) mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        v = inflater.inflate(R.layout.list_item, parent, false);
        TextView rankNumber=(TextView) v.findViewById(R.id.txtRank);
        TextView time=(TextView) v.findViewById(R.id.txtTime);
        TextView playerName=(TextView) v.findViewById(R.id.txtPlayerName);

        String timeStr=mCursor.getString(timeColIndex);
        String playerNameStr=mCursor.getString(nameColIndex);

        if(Float.parseFloat(timeStr)==(recent_time/1000f) && playerNameStr.equals(recent_playerName)) {
            v.setBackgroundColor(mContext.getResources().getColor(R.color.item_bg_recent));
            rankNumber.setText(String.valueOf(index++)+" (Your)");
        } else rankNumber.setText(String.valueOf(index++));
        time.setText(timeStr);
        playerName.setText(playerNameStr);
        mCursor.moveToNext();
        return v;           
    }
    return v;
}

@Override
public Object getItem(int id) {
    return id;
}

@Override
public long getItemId(int arg0) {
    return 0;
}

public static void setModeView(int mtime, String mplayerName) {
    recent_time=mtime;
    recent_playerName=mplayerName;
}

}

Answer 1

您更改了查询

String getData = "SELECT " + FIELD1 + "," + FIELD2 + " FROM " + TABLE_NAME;
 Cursor cursor;
   cursor = myDataBase.rawQuery(getData, null);
    while (cursor.moveToNext()) {

      //String  cursor.getColumnIndex(FIELD1);
      int id = cursor.getInt(1);
      String name = cursor.getString(0);            
}

Answer 2

我在这里看到一个可能的问题：

@Override  
public int getCount() {
    return length-1;
}

您应该写return length;，因为length=mCursor.getCount()

另一个问题是你在getView中使用游标并且只对它执行moveNext。我认为这不是一个好主意，因为获取数据并不是一个快速的过程。因此它会导致滚动滞后。尝试将完整数据集读取到内部结构列表，并在getView中使用它。

使用适配器滚动listview时错误

2 个答案: