java - 如何将列乘以ListView中的数字，Android

Question

我从数据库中选择数据。 一列中的数据，必须转换为千克，我需要乘以一列的系数。 sets_weight列中的数据以磅为单位，需要以公斤为单位显示，无需对数据库进行修改 如何正确地做到这一点。有任何想法吗!谢谢!

onSets = db.getSets(exesIdsColExes, toprog_dif);    
    listSets.setAdapter(new SimpleCursorAdapter(this, 
            R.layout.itemsets, onSets, 
            new String[] {"sets_ids", "sets_weight", "sets_ones"},  
            new int[] {R.id.itemsets_ids, R.id.itemsets_weight, R.id.itemsets_ones}) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
                View row = super.getView(position, convertView, parent);
                // Here we get the textview and set the color
                Typeface fontTitleProg = Typeface.createFromAsset(getAssets(), "AGHELVETICA.TTF");
                TextView itemsets_ids = (TextView) row.findViewById(R.id.itemsets_ids);
                itemsets_ids.setTypeface(fontTitleProg, 1);
                itemsets_ids.setGravity(0x05);

                TextView itemsets_weight = (TextView) row.findViewById(R.id.itemsets_weight);
                itemsets_weight.setTypeface(fontTitleProg, 1);
                itemsets_weight.setGravity(0x01);

                TextView itemsets_ones = (TextView) row.findViewById(R.id.itemsets_ones);
                itemsets_ones.setTypeface(fontTitleProg, 1);
                itemsets_ones.setGravity(0x01);   

                return row;
        }
    });

Answer 1

我从来没有做过任何android开发，但是the documentation of SimpleCursorAdapter说:

First, if a SimpleCursorAdapter.ViewBinder is available, setViewValue(android.view.View, android.database.Cursor, int) is invoked. If the returned value is true, binding has occured. If the returned value is false and the view to bind is a TextView, setViewText(TextView, String) is invoked. If the returned value is false and the view to bind is an ImageView, setViewImage(ImageView, String) is invoked.

因此，您只需要传递 SimpleCursorAdapter 的自定义实例，如果列索引为 1(第二列)，它将从光标获取以磅为单位的值，将其相乘以将磅转换为千克，将结果设置为 View 的文本，并返回 true。对于其他列，返回 false。