public static List<T> PutAllVal<T>(T entity, DataSet ds) where T : new() {
  List<T> lists = new List<T>();
  if (ds.Tables[0].Rows.Count > 0) {
    foreach (DataRow row in ds.Tables[0].Rows) {
      lists.Add(PutVal(new T(),row));
    }
  }
  return lists;
}
public static T PutVal<T>(T entity, DataRow row) where T : new() {
  //初始化 如果为null
  if (entity == null){
    entity = new T();
  }
  //得到类型
  Type type = typeof(T);
  //取得属性集合
  PropertyInfo[] pi = type.GetProperties();
  foreach (PropertyInfo item in pi){
    //给属性赋值
    if (row[item.Name] != null && row[item.Name] != DBNull.Value) {
      if (item.PropertyType == typeof(System.Nullable<System.DateTime>)) {
        item.SetValue(entity, Convert.ToDateTime(row[item.Name].ToString()), null);
      } else {
        item.SetValue(entity, Convert.ChangeType(row[item.Name], item.PropertyType), null);
      }
    }
  }
  return entity;
}