RecyclerView根据内容多少动态设置高度

在项目开发中我们经常会遇到需要RecyclerView和ScrollViewq嵌套的情况，一般我们都需要把RecyclerView中的内容全部显示，然后设置RV的高度为所有内容的高度+RV Padding+item 之间的Divider。
原理很简单，实现起来也很简单。

• 创建RV ViewHolder

public abstract class  MyViewHolder extends RecyclerView.ViewHolder {

    TextView tv_item;
    ImageView img_delete_item;

    public MyViewHolder(View itemView) {
        super(itemView);
        tv_item = (TextView) itemView.findViewById(R.id.tv_single);
        img_delete_item = (ImageView) itemView.findViewById(R.id.img_toprecycle_delete);
    }


    public abstract void setFixedHeight();
}

• 实现自定义VH

public MyViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.item_useview, parent, false);
        MyViewHolder viewHolder = new MyViewHolder(view){
            @Override
            public void setFixedHeight() {
                //  magic happening here
                ViewGroup.LayoutParams parentParams = parent.getLayoutParams();
                parentParams.height =
                        ((RecyclerView) parent).computeVerticalScrollRange()
                                + parent.getPaddingTop()
                                + parent.getPaddingBottom();
                parent.setLayoutParams(parentParams);
            }
        };

        return viewHolder;
    }

• 设置RV高度

//绑定viewholder
 public void onBindViewHolder(MyViewHolder holder, final int position) {
     holder.setFixedHeight();
 }