TList To DataTable

using System;  
 using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
 using System.Data;  
 using System.Collections;  
using System.Reflection;  
 namespace DatableToList  
{  
    class ConvertHelper<T> where T : new()  
     {  
        /// <summary>  
        /// 利用反射和泛型  
        /// </summary>  
        /// <param name="dt"></param>  
         /// <returns></returns>  
         public static List<T> ConvertToList(DataTable dt)  
        {  
   
             // 定义集合  
            List<T> ts = new List<T>();  
   
             // 获得此模型的类型  
            Type type = typeof(T);  
            //定义一个临时变量  
             string tempName = string.Empty;  
             //遍历DataTable中所有的数据行  
            foreach (DataRow dr in dt.Rows)  
             {  
                 T t = new T();  
                 // 获得此模型的公共属性  
                PropertyInfo[] propertys = t.GetType().GetProperties();  
                //遍历该对象的所有属性  
                foreach (PropertyInfo pi in propertys)  
               {  
                   tempName = pi.Name;//将属性名称赋值给临时变量  
                     //检查DataTable是否包含此列（列名==对象的属性名）    
                    if (dt.Columns.Contains(tempName))  
                   {  
                        // 判断此属性是否有Setter  
                       if (!pi.CanWrite) continue;//该属性不可写，直接跳出  
                        //取值  
                       object value = dr[tempName];  
                         //如果非空，则赋给对象的属性  
                         if (value != DBNull.Value)  
                            pi.SetValue(t, value, null);  
                    }  
                 }  
                 //对象添加到泛型集合中  
                ts.Add(t);  
            }  
             return ts;  
 
         }  
     }  
}  

/// <summary>
        /// 将集合类转换成DataTable
        /// </summary>
        /// <param name="list">集合</param>
        /// <returns></returns>
        public static DataTable ToDataTable(IList list)
        {
            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    result.Columns.Add(pi.Name, pi.PropertyType);
                }
                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        object obj = pi.GetValue(list[i], null);
                        tempList.Add(obj);
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }
        /// <summary>
        /// 将泛型集合类转换成DataTable
        /// </summary>
        /// <typeparam name="T">集合项类型</typeparam>
        /// <param name="list">集合</param>
        /// <returns>数据集(表)</returns>
        public static DataTable ToDataTable<T>(IList<T> list)
        {
            return ConvertX.ToDataTable<T>(list, null);
        }
        /// <summary>
        /// 将泛型集合类转换成DataTable
        /// </summary>
        /// <typeparam name="T">集合项类型</typeparam>
        /// <param name="list">集合</param>
        /// <param name="propertyName">需要返回的列的列名</param>
        /// <returns>数据集(表)</returns>
        public static DataTable ToDataTable<T>(IList<T> list, params string[] propertyName)
        {
            List<string> propertyNameList = new List<string>();
            if (propertyName != null)
                propertyNameList.AddRange(propertyName);
            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    if (propertyNameList.Count == 0)
                    {
                        result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                    else 
                    {
                        if (propertyNameList.Contains(pi.Name))
                            result.Columns.Add(pi.Name, pi.PropertyType);
                    }
                }
                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        if (propertyNameList.Count == 0)
                        {
                            object obj = pi.GetValue(list[i], null);
                            tempList.Add(obj);
                        }
                        else
                        {
                            if (propertyNameList.Contains(pi.Name))
                            {
                                object obj = pi.GetValue(list[i], null);
                                tempList.Add(obj);
                            }
                        }
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }