Question

我的Activity中有ListView，自定义SimpleCursorAdapter。自定义SimpleCursorAdapter看起来像这样。

public class MySimpleCursorAdapter extends SimpleCursorAdapter {

    private Activity activity;
    private Cursor cursor;

public MySimpleCursorAdapter(Context context, int layout, Cursor c,
String[] from, int[] to, Activity activity) {

    super(context, layout, c, from, to);
    this.activity = activity;
    this.cursor = c;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View view = convertView;
    if (view == null)
    view = View.inflate(this.activity,
         com.tour.R.layout.third_level_list_item, null);

    cursor.moveToPosition(position);

String hotelName=cursor.getString(cursor.getColumnIndexOrThrow(TodoDbAdapter.KEY_HOTEL));
String stars = cursor.getString(cursor.getColumnIndexOrThrow(TodoDbAdapter.KEY_ROW_STARS));
int numberOfStars = Integer.parseInt(stars);

TextView hotel = (TextView) view.findViewById(com.tour.R.id.hotel);
    if (hotel != null)
        hotel.setText(hotelName);

    ImageView[] images = new ImageView[5];
    images[0] = (ImageView) view.findViewById(com.tour.R.id.slika1);
    images[1] = (ImageView) view.findViewById(com.tour.R.id.slika2);
    images[2] = (ImageView) view.findViewById(com.tour.R.id.slika3);
    images[3] = (ImageView) view.findViewById(com.tour.R.id.slika4);
    images[4] = (ImageView) view.findViewById(com.tour.R.id.slika5);

    for (int i = 0; i < numberOfStars; i++)
        images[i].setVisibility(View.VISIBLE);

    return view;

}

}

CustomSimpleCursor适配器被设置为列表适配器。

代码效果很好，酒店名称还可以，星级还可以，但问题是滚动列表一段时间后，每家酒店都有5颗星，我知道这是真的。

如何管理数据库中listView中的星数。感谢。

Answer 1

我认为你只需要确保清理你的状态。您的适配器会在数据显示时显示星标。然而，当它们不是时，它们并没有使它们成为GONE / INVISIBLE。

ImageView[] images = new ImageView[5];
    images[0] = (ImageView) view.findViewById(com.tour.R.id.slika1);
    images[1] = (ImageView) view.findViewById(com.tour.R.id.slika2);
    images[2] = (ImageView) view.findViewById(com.tour.R.id.slika3);
    images[3] = (ImageView) view.findViewById(com.tour.R.id.slika4);
    images[4] = (ImageView) view.findViewById(com.tour.R.id.slika5);

    for (ImageView image : images) {
        image.setVisibility(View.INVISIBLE);
    }

    for (int i = 0; i < numberOfStars; i++)
        images[i].setVisibility(View.VISIBLE);

此外，如果您希望可以缓存该ImageView数组，以避免每次绑定单元格时遍历树的查找成本。像：

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View view = convertView;
    if (view == null) {
       view = View.inflate(this.activity, com.tour.R.layout.third_level_list_item, null);
        ImageView[] images = new ImageView[5];
        images[0] = (ImageView) view.findViewById(com.tour.R.id.slika1);
        images[1] = (ImageView) view.findViewById(com.tour.R.id.slika2);
        images[2] = (ImageView) view.findViewById(com.tour.R.id.slika3);
        images[3] = (ImageView) view.findViewById(com.tour.R.id.slika4);
        images[4] = (ImageView) view.findViewById(com.tour.R.id.slika5);
        view.setTag(images);
    }

    ImageView[] images = (ImageView[]) view.getTag();
    for (ImageView image : images) {
      image.setVisibility(View.INVISIBLE);
    }

    for (int i = 0; i < numberOfStars; i++)
      images[i].setVisibility(View.VISIBLE);

    return view;
 }

Answer 2

你永远不会让星星变得隐形。它应该是这样的：

for (int i = 0; i < numberOfStars; i++)
    images[i].setVisibility(View.VISIBLE);

for (int i = numberOfStars; i < 5; i++)
    images[i].setVisibility(View.INVISIBLE);

所有这一切：

考虑使用RatingBar代替个别明星
考虑使用持有者模式以避免在每一行进行所有findViewById()次调用
考虑致电getInt()而不是getString()，然后自己将其转换为int
由于这是CursorAdapter，理想情况下，您应该覆盖newView()和bindView()，而不是getView()

自定义SimpleCursorAdapter错误

2 个答案: