Question

我正在尝试在Android中创建一个通用适配器，所以我不能一遍又一遍地写它。

问题是，它正在工作，但它不能很好地回收利用，它会显示我想要的东西，但是当我滚动时，它的顺序不一样。

public class CustomListViewAdapter<T> extends BaseAdapter {

private List<T> objects;
private LayoutInflater inflater;
private int resources;
private AdapterCommand<T> listener;
private ViewHolder h;

public CustomListViewAdapter(Context context, List<T> objects,
        int resources, AdapterCommand<T> listener, ViewHolder h) {
    this.h = h;
    this.listener = listener;
    this.resources = resources;
    this.objects = objects;
    inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return objects.size();
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return objects.get(position);
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View v = convertView;
    if (v == null) {
        v = inflater.inflate(resources, parent, false);
        listener.init(v, h);
        v.setTag(h);
    } else {
        h = (ViewHolder) v.getTag();
    }
    T object = (T) getItem(position);
    listener.execute(object, h);
    return v;
}

public interface AdapterCommand<T> {
    public void init(View v, ViewHolder h);

    public void execute(T object, ViewHolder h);
}

public static interface ViewHolder {

}

}

Answer 1

您不能只保留一个ViewHolder实例。每次convertView为null和setTag时都需要创建新对象。

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View v = convertView;
    ViewHolder h;
    if (v == null) {
        v = inflater.inflate(resources, parent, false);
        h = new ViewHolder();
        listener.init(v, h);
        v.setTag(h);
    } else {
        h = (ViewHolder) v.getTag();
    }
    T object = (T) getItem(position);
    listener.execute(object, h);
    return v;
}

自定义Android适配器与泛型类

1 个答案: