RecyclerView新體驗（2）

在上一篇RecyclerView新體驗（1）介紹了RecyclerView的簡單使用方法和分割線的設置，但是我們仔細一看，RecyclerView並沒有給我們提供點擊事件，尼~瑪，這絕對是個坑啊，沒辦法，既然進了坑就想辦法跳出去唄。
下面我們像ListView一樣，寫出點擊和長按兩個方法。Adapter代碼如下：

public class CommonClickRecyclerViewAdapter extends RecyclerView.Adapter<CommonClickRecyclerViewAdapter.MyViewHolder> {

    private Context context;
    private List<String> list;

    //定義接口
    public interface OnItemClickListener {
        void onItemClick(View view, int position);

    } //定義接口

    public interface OnItemLongClickListener {
        void onItemLongClick(View view, int position);
    }

    //聲明接口變量
    private OnItemClickListener listener;
    //聲明接口變量
    private OnItemLongClickListener lListener;

    //暴露給使用者調用
    public void setOnItemClickListener(OnItemClickListener listener) {
        this.listener = listener;
    }

    public void setOnItemLongClickListener(OnItemLongClickListener lListener) {
        this.lListener = lListener;
    }
    private ListView lv;
    public CommonClickRecyclerViewAdapter(Context context, List<String> list) {
        this.context = context;
        this.list = list;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new MyViewHolder(LayoutInflater.from(context).inflate(R.layout.item_rcv, null));
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        holder.tv.setText(list.get(position));
        if (listener != null) {
            holder.layout.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    listener.onItemClick(view, position);
                }
            });

        }
        if (lListener != null) {
            holder.layout.setOnLongClickListener(new View.OnLongClickListener() {
                @Override
                public boolean onLongClick(View view) {
                    lListener.onItemLongClick(view, position);
                    return false;
                }
            });
        }

    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {

        TextView tv;
        RelativeLayout layout;

        public MyViewHolder(View itemView) {
            super(itemView);
            tv = (TextView) itemView.findViewById(R.id.tv);
            layout = (RelativeLayout) itemView.findViewById(R.id.rl_item);
        }
    }
}

這時候只需要我們在對RecyclerView的adapter進行監聽就好，值得注意的是回調的參數是view和當前item的position（位置），要得到相應的值可通過position進行獲取。監聽代碼如下：

adapter2.setOnItemClickListener(new CommonClickRecyclerViewAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                Log.e("一樣一樣","點擊了"+position+"元素");
            }
        });
        adapter2.setOnItemLongClickListener(new CommonClickRecyclerViewAdapter.OnItemLongClickListener() {
            @Override
            public void onItemLongClick(View view, int position) {
                Log.e("一樣一樣","點擊了"+position+"元素");
            }
        });

得到的效果如下圖：

到此，簡單的點擊和長按事件完成了，但是感覺有點不爽，每個Adapter都要自己寫點擊事件，那不是很麻煩？
我們想着點擊事件回調的是position，那也就是與實體沒有關係，於是我想到了在getview中把點擊外的抽出來一個方法，做成一個基類。注：這次寫的是一個接口回調兩個方法。

public abstract class RAdapter<T extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    //定義接口
    public interface OnItemClickListener {
        void onItemClick(View view, int position);

        void onItemLongClick(View view, int position);
    }

    //聲明接口變量
    private OnItemClickListener listener;

    //暴露給使用者調用
    public void setOnItemClickListener(OnItemClickListener listener) {
        this.listener = listener;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, final int position) {

        onBindView(viewHolder, position);

        if(listener != null) {
            viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    listener.onItemClick(view,position);
                }
            });

            viewHolder.itemView.setOnLongClickListener(new OnLongClickListener() {
                @Override
                public boolean onLongClick(View view) {
                    listener.onItemLongClick(view,position);
                    //如果是長按事件，那麼久不用再觸發點擊事件了，所以返回true
                    //將事件直接消費掉？？
                    return true;
                }
            });
        }
    }
    public abstract void onBindView(RecyclerView.ViewHolder holder, int position);
}

這時候我們寫的Adapter只要繼承了RAdapter就可以在Activity中對adapter進行監聽了，沒有必要每次都在adapte中重寫點擊事件。
自己寫的Adapter如下：

public class BaseOnClickAdapter extends RAdapter<BaseOnClickAdapter.MyViewHolder> {
    private Context context;
    private List<String> list;

    public BaseOnClickAdapter(Context context, List<String> list) {
        this.context = context;
        this.list = list;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new MyViewHolder(LayoutInflater.from(context).inflate(R.layout.item_rcv,null));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    @Override
    public void onBindView(RecyclerView.ViewHolder holder, int position) {
        if(holder instanceof MyViewHolder) {
            ((MyViewHolder) holder).tv.setText(list.get(position));
        }
    }

class MyViewHolder extends RecyclerView.ViewHolder {
    TextView tv;

    public MyViewHolder(View itemView) {
        super(itemView);
        tv = (TextView) itemView.findViewById(R.id.tv);
    }
}
}

這時候不是重寫onBindViewHolder，而是重寫onBindView（）方法就好。監聽方法：

adapter2.setOnItemClickListener(new RAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                Log.e("一樣一樣","點擊了"+position+"元素");
            }

            @Override
            public void onItemLongClick(View view, int position) {
                Log.e("一樣一樣","長按了"+position+"元素");
            }
        });

點擊和長按的結果如下

這樣是不是方便很多了呢？有更好的方法望大神不吝賜教！很晚了，就到這裏吧。