using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace POSV.Utils
{
    /// <summary>
    /// List分页
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class ListPager<T> : List<T>
    {
        /// <summary>
        /// 总记录
        /// </summary>
        public int TotalCount { get; set; }

        /// <summary>
        /// 总页数
        /// </summary>
        public int PageCount { get; set; } //总页数

        /// <summary>
        /// 当前页码
        /// </summary>
        public int PageNumber { get; set; }

        /// <summary>
        /// 每页显示记录数
        /// </summary>
        public int PageSize { get; set; } //每页显示记录数
        
        //是否有上一页
        public bool HasPreviousPage
        {
            get { return PageNumber > 1; }
        }

        //是否有下一页
        public bool HasNextPage
        {
            get { return PageNumber < this.PageCount; }
        }

        /// <summary>
        /// 构造方法
        /// </summary>
        /// <param name="dataList"></param>
        /// <param name="pageSize"></param>
        /// <param name="pageNo"></param>
        public ListPager(List<T> data , int pageSize , int pageNumber)
        {
            this.PageSize = pageSize;
            this.PageNumber = pageNumber;
            this.TotalCount = data.Count;
            this.PageCount = (this.TotalCount + this.PageSize - 1) / this.PageSize;

            this.AddRange(data.Skip((pageNumber - 1) * pageSize).Take(pageSize));
        }
    }
}