RecyclerView基础

• 用RecyclerView只需几步。

1. 实现RecyclerView.ViewHolder抽象类，把item布局的所有组件绑定在这个自定义ViewHolder上。

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView title;
        public TextView time;
        public View root;
   
    public ViewHolder(View root) {
        super(root);
        this.root=root;
        time= (TextView) root.findViewById(R.id.time);
        title= (TextView) root.findViewById(R.id.title);
    }
   
    public TextView getTime() {
        return time;
    }
   
    public TextView getTitle() {
        return title;
        }
    }
   

2.实现RecyclerView.Adapter抽象类，实现三个方法onCreateViewHolder(ViewGroup parent, int viewType)，onBindViewHolder(RecyclerView.ViewHolder holder, final int position)，getItemCount()。

• 创建VeiwHolder:

     Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        ViewHolder vh=new ViewHolder(LayoutInflater.
                from(parent.getContext()).inflate(R.layout.cell,null));
        return vh;
    }
  

• 绑定ViewHolder:

     @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
            final ViewHolder vh= (ViewHolder) holder;
            Mydata data = mydatas.get(position);
            String tit=data.getTitle();
            String tim=data.getTime();
            //赋值给textView控件
            vh.title.setText(subString(tit));
            vh.time.setText(tim);
        }
  

3.设置布局方向，有线性的，网格的。

    rv.setLayoutManager(new LinearLayoutManager(this));
    rv.setLayoutManager(new GridLayoutManager(this,3));

4.绘制分割线。要调用RecyclerView的addItemDecoration(ItemDecoration)方法，但是ItemDecoration没有实现类，只能组件通过继承ItemDecoration来实现。github有，直接引用就好了：
https://github.com/gabrielemariotti/RecyclerViewItemAnimators。

5.设置点击事件，通实现RecyclerView.OnItemTouchListener接口来设置点击事件。

• 我也是看网上的，就直接上代码了：

    public class RecyclerItemClickListener implements
    RecyclerView.OnItemTouchListener {
  private OnItemClickListener mListener;
  private GestureDetector mGestureDetector;
  // 点击回调
  public interface OnItemClickListener {
    public void onItemClick(View view, int position);
  
    public void onItemLongClick(View view, int position);
  }
  
  public RecyclerItemClickListener(Context context,
                                 final RecyclerView recyclerView, OnItemClickListener listener) {
    mListener = listener;
    // 识别并处理手势
    mGestureDetector = new GestureDetector(context,
            new GestureDetector.SimpleOnGestureListener() {
                @Override
                public boolean onSingleTapUp(MotionEvent e) {
                    // 轻击触摸屏后,弹起，必须返回true，否则无法触发单击
                    return true;
                }
  
                @Override
                public void onLongPress(MotionEvent e) {
                    // 长按
                    // 根据findChildViewUnder(float x, float y)来算出哪个item被选择了
                    View childView = recyclerView.findChildViewUnder(
                            e.getX(), e.getY());
                    // 有item被选则且监听器不为空触发长按事件
                    if (childView != null && mListener != null) {
                        mListener.onItemLongClick(childView,
                                recyclerView.getChildPosition(childView));
                    }
                }
            });
  }
  
  @Override
  public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
    View childView = view.findChildViewUnder(e.getX(), e.getY());
    if (childView != null && mListener != null
            && mGestureDetector.onTouchEvent(e)) {
        // 触发单击事件
        mListener.onItemClick(childView, view.getChildPosition(childView));
        return true;
    }
    return false;
  }
  
  @Override
  public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
  }
  
  @Override
  public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
  
  }
  }