/// <summary>    /// 将集合类转换成DataTable    /// </summary>    /// <param name="list">集合</param>    /// <returns></returns>    private 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);}foreach (object t in list){ArrayList tempList = new ArrayList();foreach (PropertyInfo pi in propertys){object obj = pi.GetValue(t, null);tempList.Add(obj);}object[] array = tempList.ToArray();result.LoadDataRow(array, true);}}return result;}

    /// <summary>    /// DataTable 转换为List 集合    /// </summary>    /// <typeparam name="TResult">类型</typeparam>    /// <param name="dt">DataTable</param>    /// <returns></returns>    public static List<T> ToList<T>(this DataTable dt) where T : class, new()  {  //创建一个属性的列表    List<PropertyInfo> prlist = new List<PropertyInfo>();  //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<PropertyInfo>(t.GetProperties(), p => { if (dt.Columns.IndexOf(p.Name) != -1) prlist.Add(p); });  //创建返回的集合
  List<T> oblist = new List<T>();  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;  }  

    /// <summary>     /// 转化一个DataTable    /// </summary>      /// <typeparam name="T"></typeparam>    /// <param name="list"></param>    /// <returns></returns>    public static DataTable ToDataTable<T>(this IEnumerable<T> list)  {    //创建属性的集合    List<PropertyInfo> pList = new List<PropertyInfo>();  //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<PropertyInfo>(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;  } 

 /// <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 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;  }
}