为统一数据相关操作，现给出数据处理相关操作的接口定义，其中包含对列表数据的增删改查等常规操作。
/** * Created by Administrator on 2016/4/19. * 适配器的数据修改方法的定义 */public interface IAdapterDataModifyHelper<T> { /** * 通知适配器更新界面 * * @param INotifyDataSetChange*/void setNotifyAdapterDataSetChange(INotifyAdapterDataSetChange INotifyDataSetChange);
/** * 获取数据集 * * @return*/List<T> getDataResources();
/** * 设置数据集 * * @param dataResources*/void setDataResource(T... dataResources);
void setDataResource(List<? extends T> dataResource);
/** * 添加数据 * * @param location* @param dataResources*/void addDataResource(int location, T... dataResources);
void addDataResource(int location, List<? extends T> dataResources);
void addFirstDataResource(T... dataResources);
void addFirstDataResource(List<T> dataResources);
void addEndDataResource(T... dataResources);
void addEndDataResource(List<T> dataResources);
/** * 修改元素 * * @param position* @param enity*/void reviseDataResource(int position, T enity);
/** * 移除指定元素 */void removeDataResource(T removedEntiy);
/** * 移除指定位置的元素 * * @param position*/void removeDataResourceOnPosition(int position);
/** * 清空所有数据集 */void clear();
/** * 修正带操作的数据索引下标 * * @param location* @return*/int proofOperateDataLocation(int location);
/** * 判断操作的location位置是否正确 * * @return*/boolean isOperateLocationRight(int position);}
IAdapterDataModifyHelper的实现类DataModifyHelper的部分源码如下：
/** * @Description:针对数据的相关处理Helper类* @author: Xiaoxuan948 * @date: 2016/7/20 20:37 */public class DataModifyHelper<T> implements IAdapterDataModifyHelper<T> { private final UtilsLog lg = UtilsLog.getLogger(DataModifyHelper.class); protected List<T> mDataResources; private INotifyAdapterDataSetChange INotifyDataSetChange;
public DataModifyHelper() { this.mDataResources = new ArrayList<>();}
@Overridepublic void setNotifyAdapterDataSetChange(INotifyAdapterDataSetChange INotifyDataSetChange) { this.INotifyDataSetChange = INotifyDataSetChange;}
@Overridepublic List<T> getDataResources() { return mDataResources;}
@Overridepublic void setDataResource(List<? extends T> setDataResources) { /*针对集合空数据进行处理*/if (UtilsCollections.isCollectionNotEmpty(setDataResources) && setDataResources.contains(null)) { lg.e("setDataResource集合包含null数据");setDataResources = Lists.newArrayList(Collections2.filter(setDataResources, new Predicate<T>() { @Overridepublic boolean apply(T input) { return input != null;} }));} if (!UtilsCollections.isCollectionNotEmpty(setDataResources)) { return;} /*针对类型不匹配进行处理*/this.mDataResources = Lists.transform(setDataResources, new Function<Object, T>() { @Overridepublic T apply(Object input) { return (T) input;} });INotifyDataSetChange.notifyAdapter();}
@Overridepublic void addDataResource(int location, List<? extends T> addDataResources) { if (UtilsCollections.isCollectionNotEmpty(addDataResources) && addDataResources.contains(null)) { lg.e("addDataResource集合包含null数据");addDataResources = Lists.newArrayList(Collections2.filter(addDataResources, new Predicate<T>() { @Overridepublic boolean apply(T input) { return input != null;} }));} if (!UtilsCollections.isCollectionNotEmpty(addDataResources)) { lg.e("addDataResource:待加入的集合为空"); return;} location = proofOperateDataLocation(location); this.mDataResources.addAll(location, addDataResources);INotifyDataSetChange.notifyAdapter();}
@Overridepublic void reviseDataResource(int position, T enity) { if (isOperateLocationRight(position)) { this.mDataResources.set(position, enity);INotifyDataSetChange.notifyAdapter();} else { lg.e("reviseDataResource failed because position out of size " + this.mDataResources.size());} }
@Overridepublic void removeDataResourceOnPosition(int position) { this.mDataResources.remove(position);INotifyDataSetChange.notifyAdapter();}
@Overridepublic void clear() { this.mDataResources.clear();INotifyDataSetChange.notifyAdapter();}
@Overridepublic boolean isOperateLocationRight(int position) { return !(position < 0 || position > this.mDataResources.size());}
@Overridepublic int proofOperateDataLocation(int location) { int newLocation = location < 0 ? 0 : location > this.mDataResources.size() ? this.mDataResources.size() : location;lg.e("proofOperateDataLocation from " + location + " to " + newLocation); return newLocation;}}
观察可知，在DataModifyHelper构造函数中实例化mDataResources对象，其对应于列表控件中显示的数据。
setNotifyAdapterDataSetChange为外界提供数据更新的接口注入方法，在数据修改后调用INotifyDataSetChange的notifyAdapter()方法即可通知适配器更新。
setDataResource方法中，针对List数据先进行非空过滤，再判断List非空后进行数据修改，以确保mDataResources集合始终非空。这里会注意到其参数使用无限制通配符，这里是提高程序扩展性，当适配器基于接口编程时能方便set数据。（提示：List<Child>无法转为List<Parent>）
addDataResource的实现过程同setDataResource基本一致，都是针对数据集进行非空等一系列处理。
接下来考虑定义BaseAdapter抽象基类，抽取共性部分，即实现getCount、getItem、getItemId
观察源码可知，在构造函数中实例化DataModifyHelper对象，该对象负责数据的增删改查等操作。适配器中提供getDataModifyHelper方法，供外界获得操作数据的DataModifyHelper帮助类。
public abstract class AbsUnityBaseAdapter<T> extends BaseAdapter implements INotifyAdapterDataSetChange { private static final UtilsLog lg = UtilsLog.getLogger(AbsUnityBaseAdapter.class); private LayoutInflater layoutInflater; private IAdapterDataModifyHelper<T> IAdapterataModifyHelper;
/** * 构造方法 */protected AbsUnityBaseAdapter() { this.IAdapterataModifyHelper = new DataModifyHelper<>();}
public IAdapterDataModifyHelper<T> getDataModifyHelper() { this.IAdapterataModifyHelper.setNotifyAdapterDataSetChange(this); return IAdapterataModifyHelper;}
@Overridepublic void notifyAdapter() { notifyDataSetChanged();}
/** * default method */@Overridepublic int getCount() { return IAdapterataModifyHelper.getDataResources().size();}
@Overridepublic T getItem(int position) { //可能数组越界if (position >= IAdapterataModifyHelper.getDataResources().size()) { lg.e("getItem:index " + position + " is out of size " + IAdapterataModifyHelper.getDataResources().size()); return null;} return IAdapterataModifyHelper.getDataResources().get(position);}
@Overridepublic long getItemId(int position) { return position;}
@Overridepublic View getView(int position, View convertView, ViewGroup parent) { UnityAdapterViewHolder helper = null; if (convertView != null) { helper = (UnityAdapterViewHolder) convertView.getTag();} else { if (layoutInflater == null) { layoutInflater = LayoutInflater.from(parent.getContext());} helper = new UnityAdapterViewHolder(layoutInflater, getLayoutId(), parent);} convert(IAdapterataModifyHelper.getDataResources().get(position), helper, position); return helper.getConvertView();}
/*自定义抽象方法*/public abstract void convert(T itemEntity, UnityAdapterViewHolder helper, int position);
public abstract int getLayoutId();}
分析getView部分源码可知，其基于UnityAdapterViewHolder类封装ViewHolder模式，构造方法如下：
/** * Created by Administrator on 2015/8/25. */public class UnityAdapterViewHolder { private SparseArray<View> views; private View convertView;
public UnityAdapterViewHolder(LayoutInflater layoutInflater, int layoutId, ViewGroup parent) { this.views = new SparseArray<>(); this.convertView = layoutInflater.inflate(layoutId, parent, false); this.convertView.setTag(this);}
public View getConvertView() { return convertView;}
/** * generateView * * @param viewId* @param <T>* @return*/protected <T extends View> T generateView(int viewId) { View view = views.get(viewId); if (view == null) { view = convertView.findViewById(viewId);views.put(viewId, view);} return (T) view;}
/** * @param viewId* @param clz* @param <T>* @return*/public <T extends View> T generateView(int viewId, Class<T> clz) { return generateView(viewId);}}
业务层使用方式如下：
adapter = new AbsUnityBaseRecyclerAdapter<CorePageEntity>() { @Overridepublic void convert(CorePageEntity itemEntity, UnityRecyclerAdapterViewHolder viewHolder, int position) { viewHolder.generateView(R.id.tvItemCommon, TextView.class).setText(itemEntity.getCorePageTitle());}
@Overridepublic int getItemLayoutId(int viewType) { return R.layout.simple_item_horizontal;}};
对于数据修改等操作，
adapter.getDataModifyHelper().setDataResource( CorePageEntity.create(TestActivity.class),CorePageEntity.create(PullToRefreshActivity.class));
时间： 2024-10-13 01:07:17