DataTable转List 泛型集合扩展方法分享

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.ComponentModel.DataAnnotations;
using System.Runtime.CompilerServices;
using System.Data;

namespace System
{
    /// <summary>
    /// table转list
    /// </summary>
    public static class DataTableExtend
    {
        public static List<T> ToList<T>(this DataTable dt) where T : class,new()
        {
            var list = new List<T>();
            Type type = typeof(T).GetType();
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                T model = new T();
                var dr = dt.Rows[i];
                //字段集合
                PropertyInfo[] listPro = model.GetType().GetProperties().Where(item=>item.IsDefined(typeof(InternalAttribute),false)).ToArray();
                for (int j = 0; j < listPro.Length; j++)
                {
                    var pi = listPro[i];
                    var columnName = pi.Name;//字段
                    var columnType = pi.PropertyType;//字段类型
                    Type underlyingType = Nullable.GetUnderlyingType(columnType);
                    if (dt.Columns.Contains(columnName))
                    {
                        if (!pi.CanWrite) continue;
                        object value = dr[columnName];
                        if (value == DBNull.Value) continue;

                        if (pi.PropertyType == typeof(string))
                            pi.SetValue(model, value.ToString(), null);
                        else if (pi.PropertyType == typeof(int) || pi.PropertyType == typeof(int?))
                            pi.SetValue(model, Convert.ToInt32(value), null);
                        else if (pi.PropertyType == typeof(DateTime) || pi.PropertyType == typeof(DateTime?))
                            pi.SetValue(model, Convert.ToDateTime(value), null);
                        else if (pi.PropertyType == typeof(float))
                            pi.SetValue(model, Convert.ToSingle(value), null);
                        else if (pi.PropertyType == typeof(decimal))
                            pi.SetValue(model, Convert.ToDecimal(value), null);
                        else if (pi.PropertyType == typeof(double))
                            pi.SetValue(model, Convert.ToDouble(value), null);
                        else if ((underlyingType ?? columnType).IsEnum)
                        {//判断枚举属性为空的属性赋值
                            if (underlyingType != null && !string.IsNullOrEmpty(value.ToString()))
                                pi.SetValue(model, Enum.Parse(underlyingType ?? type, value.ToString()), null);
                            else if (underlyingType == null && !string.IsNullOrEmpty(value.ToString()))
                                pi.SetValue(model, Convert.ToInt32(value), null);
                            else
                                pi.SetValue(model, -1, null);
                        }
                        else
                            pi.SetValue(model, value, null);
                    }

                }
                list.Add(model);
            }

            return list;
        }
    }
}