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

namespace Pcb.Common
{
    /// <summary>
    /// 列表扩展
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public static class extEnumerable
    {
        #region 转换成散列集合
        /// <summary>
        /// 转换成HashSet
        /// </summary>
        /// <typeparam name="T">列表项类型</typeparam>
        /// <param name="List">枚举列表</param>
        /// <returns>HashSet</returns>
        public static HashSet<T> _ToHashSet<T>(this IEnumerable<T> List)
        {
            var hs = new HashSet<T>();
            foreach (var i in List) { hs.Add(i); }
            return hs;
        }
        /// <summary>
        /// 转换成HashSet
        /// </summary>
        /// <typeparam name="T">列表项类型</typeparam>
        /// <param name="List">枚举列表</param>
        /// <returns>HashSet</returns>
        public static HashSet<T> _ToHashSet<T>(this IEnumerable List)
        {
            var hs = new HashSet<T>();
            foreach (T i in List) { hs.Add(i); }
            return hs;
        }
        /// <summary>
        /// 转换成HashSet
        /// </summary>
        /// <typeparam name="T">列表项类型</typeparam>
        /// <typeparam name="TValue">其它类型</typeparam>
        /// <param name="List">枚举列表</param>
        /// <param name="Select">选择键函数</param>
        /// <returns>数组</returns>
        public static HashSet<TValue> _ToHashSet<T, TValue>(this IEnumerable<T> List, Func<T, TValue> Select)
        {
            var hs = new HashSet<TValue>();
            foreach (var i in List) { hs.Add(Select(i)); }
            return hs;
        }
        /// <summary>
        /// 转换成HashSet
        /// </summary>
        /// <typeparam name="T">列表项类型</typeparam>
        /// <typeparam name="TValue">其它类型</typeparam>
        /// <param name="List">枚举列表</param>
        /// <param name="Select">选择键函数</param>
        /// <returns>数组</returns>
        public static HashSet<TValue> _ToHashSet<T, TValue>(this IEnumerable List, Func<T, TValue> Select)
        {
            var hs = new HashSet<TValue>();
            foreach (T i in List) { hs.Add(Select(i)); }
            return hs;
        }
        /// <summary>
        /// 转换成其它类型列表
        /// </summary>
        /// <typeparam name="TValue">其它类型</typeparam>
        /// <param name="List">数据行列表</param>
        /// <param name="Select">选择键函数</param>
        /// <returns>列表</returns>
        public static HashSet<TValue> _ToHashSet<TValue>(this System.Data.DataRowCollection List, Func<System.Data.DataRow, TValue> Select)
        {
            HashSet<TValue> lst = new HashSet<TValue>();
            foreach (System.Data.DataRow i in List) { lst.Add(Select(i)); }
            return lst;
        }
        /// <summary>
        /// 转换成其它类型列表
        /// </summary>
        /// <typeparam name="TValue">其它类型</typeparam>
        /// <param name="List">数据行列表</param>
        /// <param name="Select">选择键函数</param>
        /// <returns>列表</returns>
        public static HashSet<TValue> _ToHashSet<TValue>(this System.Data.DataColumnCollection List, Func<System.Data.DataColumn, TValue> Select)
        {
            HashSet<TValue> lst = new HashSet<TValue>();
            foreach (System.Data.DataColumn i in List) { lst.Add(Select(i)); }
            return lst;
        }
        #endregion
    }
}