Question

我想知道是否有人可以进一步解释如何在从SQLite数据库填充的列表视图中实现删除按钮。我已经阅读了以下问题的回复，这些问题基本上也是我所要求的，但我不理解它：

How can I implement a delete button in a ListView and delete from database?

在我的自定义行.xml文件中，我包含了一个删除按钮，用于实现方法delete（）onClick。顺便说一下，它还包括一个警报对话框。这是我到目前为止我的delete（）方法的代码;每当我尝试使用它时，它永远不会获得正确的活动条目。

  public void delete(View view){

    final int position = listview.getPositionForView((View) view.getParent());
    String id = cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_ID));

    AlertDialog.Builder myDialog = new AlertDialog.Builder(MainActivity.this);

    myDialog.setTitle("Delete activity entry \"" + id + "\"?");
    myDialog.setPositiveButton("DELETE", new DialogInterface.OnClickListener() {

        public void onClick(DialogInterface arg0, int arg1) {
            mySQLiteAdapter.delete(position);
            cursor.requery();
            }
        });

    myDialog.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {

        public void onClick(DialogInterface arg0, int arg1) {

            }
        });

    myDialog.show();
}

Answer 1

解决方案是实现自定义ArrayAdapter。

 public class MyArrayAdapter extends ArrayAdapter<YourObject>
    {

        private ArrayList<YourObject> items;

        public LiftArrayAdapter(Context context, int textViewResourceId, ArrayList<YourObject> items)
        {
            super(context, textViewResourceId, items);
            this.items = items;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent)
        {
            View v = convertView;
            if (v == null)
            {
                LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                v = vi.inflate(R.layout.your_view_xml, null);


}
        final YourObject obj = items.get(position);

        TextView lblLift = (TextView) v.findViewById(R.id.lbl_lift);
        ImageButton btnDelete = (ImageButton) v.findViewById(R.id.btn_delete);

        btnDelete .setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                //TODO delete 'obj' from database
            }
        });

        return v;
    }

}

然后，将对象列表绑定到listview：

    List<YourObject> list = ...
    MyArrayAdapter myArrayAdapter = new MyArrayAdapter (.., .. ,  list);
    listView.setAdapter(myArrayAdapter);

从SQLiteDatabase中删除Listview中的按钮

1 个答案: