我拥有的：

在我的MainActivity我有一个ListView.我使用sqlite数据库,并使用扩展SimpleCursorAdapter的自定义适配器填充ListView.通过单击我的ActionBar中的项目,我激活上下文动作模式.一切工作到目前为止.

我想要的是：

通过点击ListView项目中的某个图标,应该删除相应的数据库行,并且应该刷新ListView.

我的问题：

如何正确刷新我的光标和我的ListView？当我不在我的OnClickListener中使用cursor.requery()并且使用cursor = dbm.getIOIOSensorsCursor()而不是在行下面的几行CursorIndexOutOfBoundsException

int state = cursor.getInt(cursor.getColumnIndex(IOIOSensorSchema.STATE));

我的应用程序崩溃,但重新加载后,数据库已被删除,并且相应的ListView项目已经消失.

我猜,在get get方法中,崩溃必须与_position有关,因为_position是final.但是,当我使用cursor.requery()一切都可以正常工作.

但是这种方法已被弃用,文档说“不要使用…”.我是一个正确编码的朋友(我还是一个初学者,想要学习编码正确的方式,而不是快速而脏),并想知道如何做到这一点.我不知道这是否重要,但我只是在我的(真正快速的)Nexus 4上测试我的应用程序.似乎没有任何问题刷新光标足够快,但我不知道它是否可以在较慢的设备上工作.万一重要的是,我的数据库将包含大约10-20行和大约12列.我想这是一个非常小的数据库.

以下是我的自定义适配器的相关代码：

public class IOIOSensorCursorAdapterCam extends SimpleCursorAdapter
{
static class ViewHolder
{
ImageView stateIV,removeIV;
TextView nameTV,pinNumberTV,FeedIDTV,freqTV;
}
 
private Context ctx;
private Cursor cursor;
private IodDatabaseManager dbm;
 
public IOIOSensorCursorAdapterCam(Context _context,int _layout,Cursor _cursor,String[] _from,int[] _to,int _flags)
{
super(_context,_layout,_cursor,_from,_to,_flags);
ctx = _context;
cursor = _cursor;
dbm = new IodDatabaseManager(_context);
}
 
@Override
public View getView(final int _position,View _convertView,ViewGroup _parent)
{
ViewHolder holder = null;
 
LayoutInflater inflater = (LayoutInflater) ctx
    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 
// There is no view at this position,we create a new one. In this case
// by inflating an xml layout.
if (_convertView == null)
{
    // Inflate a layout
    _convertView = inflater.inflate(R.layout.listview_item_sensor_cam,null);
 
    holder = new ViewHolder();
    holder.stateIV = (ImageView) _convertView
        .findViewById(R.id.stateImageView);
    holder.nameTV = (TextView) _convertView
        .findViewById(R.id.sensorNameTextView);
    holder.pinNumberTV = (TextView) _convertView
        .findViewById(R.id.sensorPinNumberTextView);
    holder.FeedIDTV = (TextView) _convertView
        .findViewById(R.id.sensorFeedIDTextView);
    holder.freqTV = (TextView) _convertView
        .findViewById(R.id.sensorFrequencyTextView);
    holder.removeIV = (ImageView) _convertView
        .findViewById(R.id.removeImageView);
    _convertView.setTag(holder);
}
// We recycle a View that already exists.
else
{
    holder = (ViewHolder) _convertView.getTag();
}
 
// Set an OnClickListener to the "Delete Icon"
holder.removeIV.setOnClickListener(new OnClickListener()
{
    @SuppressWarnings("deprecation")
    @Override
    public void onClick(View _view)
    {
    cursor.moveToPosition(_position);
 
    // Delete sensor from database here
    int sensorID = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.SENSOR_ID));
    dbm.deleteIOIOSensor(sensorID);
 
    // This leads to a "CursorIndexOutOfBoundsException" and cannot
    // be used to refresh the ListView
//      cursor = dbm.getIOIOSensorsCursor();
 
    // Refresh ListView
    cursor.requery();
    notifyDataSetChanged();
    }
});
 
cursor.moveToPosition(_position);
 
if (cursor.getCount() > 0)
{
    int state = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.STATE));
 
    if (state == 0)
    {
    holder.stateIV.setImageResource(R.drawable.av_play_over_video);
    holder.stateIV.setColorFilter(ctx.getResources().getColor(
        R.color.hint_lighter_gray));
    // _convertView.setAlpha((float) 0.5);
    holder.nameTV.setTextColor(ctx.getResources().getColor(
        R.color.hint_darker_gray));
    }
    else
    {
    holder.stateIV.setImageResource(R.drawable.av_pause_over_video);
    holder.stateIV.setColorFilter(ctx.getResources().getColor(
        android.R.color.holo_green_light));
    // _convertView.setAlpha((float) 1);
    holder.nameTV.setTextColor(ctx.getResources().getColor(
        android.R.color.black));
    }
 
    // Set the sensor's name to the according TextView
    String sensorName = cursor.getString(cursor
        .getColumnIndex(IOIOSensorSchema.NAME));
    holder.nameTV.setText(sensorName);
 
    // Set the sensor's pin number to the according TextView
    int pinNumber = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.PIN_NUMBER));
    holder.pinNumberTV.setText("" + pinNumber);
 
    // Set the sensor's Feed ID to the according TextView
    int FeedID = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.Feed_ID));
    holder.FeedIDTV.setText("" + FeedID);
 
    // Set the sensor's frequency to the according TextView
    int frequency = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.FREQUENCY));
    int timeUnit = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.TIME_UNIT));
    String frequencyTextViewText = "";
    switch (timeUnit)
    {
    case IodioIOSensor.TIME_UNIT_MINUTES:
    frequencyTextViewText = frequency + " min";
    break;
    case IodioIOSensor.TIME_UNIT_HOURS:
    frequencyTextViewText = frequency + " h";
    break;
    default:
    frequencyTextViewText = frequency + " sec";
    break;
    }
    holder.freqTV.setText(frequencyTextViewText);
}
return _convertView;
}
}

编辑：

在实现解决方案之后,这是OnCickListener的相关代码：

// Set an OnClickListener to the "Delete Icon"
holder.removeIV.setOnClickListener(new OnClickListener()
{
    @Override
    public void onClick(View _view)
    {
    cursor.moveToPosition(_position);
 
    // Delete sensor from database here
    int sensorID = cursor.getInt(cursor
        .getColumnIndex(IOIOSensorSchema.SENSOR_ID));
    dbm.deleteIOIOSensor(sensorID);
 
    Toast.makeText(ctx,R.string.toast_sensor_deleted,Toast.LENGTH_SHORT).show();
 
    // Refresh ListView
    cursor = dbm.getIOIOSensorsCursor();
    swapCursor(cursor);
 
    notifyDataSetChanged();
    }
});