集合转datatable

public static class IEnumerableExtensions
   {
       public static DataTable AsDataTable<T>(this IEnumerable<T> data)
       {
           PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
           var table = new DataTable();
           foreach (PropertyDescriptor prop in properties)
               table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
           foreach (T item in data)
           {
               DataRow row = table.NewRow();
               foreach (PropertyDescriptor prop in properties)
                   row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
               table.Rows.Add(row);
           }
           return table;
       }
   }