C# Table转换List 或List转换Table

    public static class TableListHelper
     {
 
         ///

 
         /// 转化一个DataTable 
         ///

 
         ///  
         ///  
         ///  
         public static DataTable ToDataTable(this IEnumerable list)
         {
             //创建属性的集合 
             List pList = new List();
             //获得反射的入口 
             Type type = typeof(T);
             DataTable dt = new DataTable();
             //把所有的public属性加入到集合 并添加DataTable的列 
             Array.ForEach(type.GetProperties(), p => { pList.Add(p); dt.Columns.Add(p.Name, p.PropertyType); });
             foreach (var item in list)
             {
                 //创建一个DataRow实例 
                 DataRow row = dt.NewRow();
                 //给row 赋值 
                 pList.ForEach(p => row[p.Name] = p.GetValue(item, null));
                 //加入到DataTable 
                 dt.Rows.Add(row);
             }
             return dt;
         }
 
 
         ///

 
         /// DataTable 转换为List 集合 
         ///

 
         /// 类型 
         /// DataTable 
         ///  
         public static List ToList(this DataTable dt) where T : class, new()
         {
             //创建一个属性的列表 
             List prlist = new List();
             //获取TResult的类型实例  反射的入口 
 
             Type t = typeof(T);
 
             //获得TResult 的所有的Public 属性 并找出TResult属性和DataTable的列名称相同的属性(PropertyInfo) 并加入到属性列表  
             Array.ForEach(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });
 
             //创建返回的集合 
 
             List oblist = new List();
 
             foreach (DataRow row in dt.Rows)
             {
                 //创建TResult的实例 
                 T ob = new T();
                 //找到对应的数据  并赋值 
                 prlist.ForEach(p => { if (row[p.Name] != DBNull.Value) p.SetValue(ob, row[p.Name], null); });
                 //放入到返回的集合中. 
                 oblist.Add(ob);
             }
             return oblist;
         }
 
 
         ///

 
         /// 将集合类转换成DataTable 
         ///

 
         /// 集合 
         ///  
         public static DataTable ToDataTableTow(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;
         }
 
 
         ///

 
         /// 将泛型集合类转换成DataTable 
         ///

 
         /// 集合项类型 
         /// 集合 
         /// 需要返回的列的列名 
         /// 数据集(表) 
         public static DataTable ToDataTable(IList list, params string[] propertyName)
         {
             List propertyNameList = new List();
             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;
         }
 
     }