qlhb/Ropin.Core.Common/EnumerableHelper.cs

using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Linq.Expressions;
using System.Numerics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Ropin.Core.Common
{
    public static class EnumerableHelper
    {
        public static DataTable ToPivotTable<T, TColumn, TRow, TData>(this IEnumerable<T> source, Func<T, TColumn> columnSelector, Expression<Func<T, TRow>> rowSelector, Func<IEnumerable<T>, TData> dataSelector)
        {
            DataTable table = new DataTable();
            var rowName = ((MemberExpression)rowSelector.Body).Member.Name;
            table.Columns.Add(new DataColumn(rowName));
            var columns = source.Select(columnSelector).Distinct();

            foreach (var column in columns)
            {
                table.Columns.Add(new DataColumn(column.ToString()));
            }

            var rows = source.GroupBy(rowSelector.Compile())
                             .Select(rowGroup => new
                             {
                                 Key = rowGroup.Key,
                                 Values = columns.GroupJoin(
                                     rowGroup,
                                     c => c,
                                     r => columnSelector(r),
                                     (c, columnGroup) => dataSelector(columnGroup))
                             });

            foreach (var row in rows)
            {
                var dataRow = table.NewRow();
                var items = row.Values.Cast<object>().ToList();
                items.Insert(0, row.Key);
                //List<object> list = new List<object>();
                //foreach (var vals in items)
                //{
                //    var va = GetValues(vals.ToString());
                //    list.Add(va);
                //}
                dataRow.ItemArray = items.ToArray();
                table.Rows.Add(dataRow);
            }

            return table;
        }
        public static string GetValues(string value)
        {
            //bool isInteger = Regex.IsMatch(value, @"^\d+$");
            bool isDecimal = Regex.IsMatch(value, @"^\d+(\.\d+)?$");
            bool bol = true;
            if (isDecimal)
            {
                var spl= value.Split('.');
                if (spl.Count()>=2&&value.Split('.')?[1].Length > 3)
                {
                    bol = false;
                }
            }
            if (bol) { return value; }
            else { return Convert.ToDecimal(value).ToString("F3"); }
        }
    }
}