如何优雅的写代码——使用RecyleView的基类Adapter

来源：互联网发布：网络组建总结编辑：程序博客网时间：2024/05/29 16:38

使用基类是代码更清晰也更简单，就是容易看也容易写。平常写个Adapter可能又长又乱，现在可以这样写了：

public class AppListAdapter extends RecycleVariableAdapter<AppViewHolder, AppInfo> {    public AppListAdapter(Context context, List<AppInfo> data) {        super(context, data);    }    @Override    public AppViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = inflater.inflate(R.layout.item_app_list, parent, false);        return new AppViewHolder(view);    }    @Override    public void onBindViewHolder(AppViewHolder holder, int position) {        final AppInfo appInfo = data.get(position);        holder.appName.setText(appInfo.getName());        holder.appSize.setText(appInfo.getSize());        WpPicasso.with(context)                .load(appInfo.getIcon())                .placeholder(R.drawable.ic_appstore_default_icon)                .into(holder.icon);    }}

是不是很简单，不过这里还需要自定义一个ViewHolder，像这样：

class AppViewHolder extends RecyclerHolder {    ImageView icon;    TextView appName;    TextView appSize;    public AppViewHolder(View view) {        super(view);        icon = ViewFinder.find(view, R.id.icon);        appName = ViewFinder.find(view, R.id.app_name);        appSize = ViewFinder.find(view, R.id.app_size);    }}

就三个步骤，建一个ViewHolder；为ViewHoder绑定view；根据data设置ViewHolder的View。

这个基类写也很简单，还可以自己添加项目所需的方法进去。下面是我使用的基类，还是很简单的。

public abstract class RecycleVariableAdapter<Holder extends RecyclerHolder, T> extends RecyclerView.Adapter<Holder> implements Variable<T> {    /** adapter 数据集 */    public List<T> data;    /** Context */    protected Context context;    /** 用于解析布局 */    protected LayoutInflater inflater;    public RecycleVariableAdapter(Context context, List<T> data) {        this.context = context;        this.data = data;        inflater = LayoutInflater.from(context);    }    public Context getContext(){        return this.context;    }    @Override    public int getItemCount() {        return data != null ? data.size() : 0;    }    /**     * 是否是个空的     * @return     */    public boolean isEmpty(){        return getItemCount() == 0;    }    //兼容处理．    public T getItem(int position){        return data.get(position);    }    /**     * 判断非空     * @param adapter     * @return     */    public static boolean checkEmpty(RecycleVariableAdapter adapter){        return adapter == null || adapter.isEmpty();    }    @Override    public void refresh(List<T> data) {        this.data.clear();        this.data = data;        notifyDataSetChanged();    }    @Override    public void append(T data) {        this.data.add(data);        notifyItemInserted(this.data.size() - 1);    }    @Override    public void append(int position, T data) {        this.data.add(position,data);        notifyItemInserted(position);    }    @Override    public void append(List<T> data) {        int oldSize = this.data.size();        this.data.addAll(data);        notifyItemRangeInserted(oldSize, data.size());    }    @Override    public T remove(T item) {        this.data.remove(item);        notifyItemRemoved(this.data.size() + 1);        return item;    }    @Override    public T remove(int position) {        T item = this.data.get(position);        this.data.remove(position);        notifyItemRemoved(position);        return item;    }    public void removeAll() {        this.data.clear();        notifyDataSetChanged();    }}

public class RecyclerHolder extends RecyclerView.ViewHolder {    public View rootView;    public RecyclerHolder(View itemView) {        super(itemView);        rootView = itemView;    }}

这个基类还加了一些数据的处理方法，方便使用。

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