• 利用反射将Datatable、SqlDataReader转换成List模型


    1. DataTable转IList

     1 public class DataTableToList<T>whereT :new()
     2 
     3 {
     4 
     5 ///<summary>
     6 
     7 ///利用反射将Datatable转换成List模型
     8 
     9 ///</summary>
    10 
    11 ///<param name="dt"></param>
    12 
    13 ///<returns></returns>
    14 
    15 public static List<T> ConvertToList(DataTabledt)
    16 
    17 {
    18 
    19 List<T> list =newList<T>();
    20 
    21 Typetype =typeof(T);
    22 
    23 stringtempName =string.Empty;
    24 
    25 foreach(DataRowdrindt.Rows)
    26 
    27 {
    28 
    29 T t =newT();
    30 
    31 PropertyInfo[] propertys =
    32 t.GetType().GetProperties();
    33 
    34 foreach(PropertyInfopiinpropertys)
    35 
    36 {
    37 
    38 tempName = pi.Name;
    39 
    40 if(dt.Columns.Contains(tempName))
    41 
    42 {
    43 
    44 if(!pi.CanWrite)
    45 
    46 {
    47 
    48 continue;
    49 
    50 }
    51 
    52 var value = dr[tempName];
    53 
    54 if(value !=DBNull.Value)
    55 
    56 {
    57 
    58 pi.SetValue(t, value,null);
    59 
    60 }
    61 
    62 }
    63 
    64 }
    65 
    66 list.Add(t);
    67 
    68 }
    69 
    70 returnlist;
    71 
    72 }
    73 
    74 }

    2. SqlDataReader转IList

     1         /// <summary>
     2         /// 判断SqlDataReader是否存在某列
     3         /// </summary>
     4         /// <param name="dr">SqlDataReader</param>
     5         /// <param name="columnName">列名</param>
     6         /// <returns></returns>
     7         private bool readerExists(SqlDataReader dr, string columnName)
     8         {
     9 
    10             dr.GetSchemaTable().DefaultView.RowFilter = "ColumnName= '" + columnName + "'";
    11 
    12             return (dr.GetSchemaTable().DefaultView.Count > 0);
    13 
    14         }
    15 
    16         ///<summary>
    17         ///利用反射和泛型将SqlDataReader转换成List模型
    18         ///</summary>
    19         ///<param name="sql">查询sql语句</param>
    20         ///<returns></returns>
    21 
    22         public IList<T> ExecuteToList<T>(string sql) where T : new()
    23 
    24         {
    25             IList<T> list;
    26 
    27             Type type = typeof (T);
    28 
    29             string tempName = string.Empty;
    30 
    31             using (SqlDataReader reader = ExecuteReader(sql))
    32             {
    33                 if (reader.HasRows)
    34                 {
    35                     list = new List<T>();
    36                     while (reader.Read())
    37                     {
    38                         T t = new T();
    39 
    40                         PropertyInfo[] propertys = t.GetType().GetProperties();
    41 
    42                         foreach (PropertyInfo pi in propertys)
    43                         {
    44                             tempName = pi.Name;
    45 
    46                             if (readerExists(reader, tempName))
    47                             {
    48                                 if (!pi.CanWrite)
    49                                 {
    50                                     continue;
    51                                 }
    52                                 var value = reader[tempName];
    53 
    54                                 if (value != DBNull.Value)
    55                                 {
    56                                     pi.SetValue(t, value, null);
    57                                 }
    58 
    59                             }
    60 
    61                         }
    62 
    63                         list.Add(t);
    64 
    65                     }
    66                     return list;
    67                 }
    68             }
    69             return null;
    70         }

    3、结果集从存储过程获取

     1   /// <summary>
     2         /// 处理存储过程
     3         /// </summary>
     4         /// <param name="spName">存储过程名</param>
     5         /// <param name="parameters">参数数组</param>
     6         /// <returns>sql数据流</returns>
     7         protected virtual SqlDataReader ExecuteReaderSP(string spName, ArrayList parameters)
     8         {
     9             SqlDataReader result = null;
    10             cmd.CommandText = spName;
    11             cmd.CommandType = CommandType.StoredProcedure;
    12             cmd.Parameters.Clear();
    13             if (parameters != null)
    14             {
    15                 foreach (SqlParameter param in parameters)
    16                 {
    17                     cmd.Parameters.Add(param);
    18                 }
    19             }
    20             try
    21             {
    22                 Open();
    23                 result = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    24             }
    25             catch (Exception e)
    26             {
    27                 if (result != null && (!result.IsClosed))
    28                 {
    29                     result.Close();
    30                 }
    31                 LogHelper.WriteLog("
    方法异常【ExecuteReaderSP(string spName, ArrayList parameters)】" + spName, e);
    32                 throw new Exception(e.Message);
    33             }
    34             return result;
    35         }
     1 <strong>      </strong> ///<summary>
     2         ///利用反射将SqlDataReader转换成List模型
     3         ///</summary>
     4         ///<param name="spName">存储过程名称</param>
     5         ///<returns></returns>
     6 
     7         public IList<T> ExecuteQueryListSP<T>(string spName, params SqlParameter[] listParams) where T : new()
     8         {
     9             IList<T> list;
    10 
    11             Type type = typeof(T);
    12 
    13             string tempName = string.Empty;
    14 
    15             using (SqlDataReader reader = ExecuteReaderSP(spName, new ArrayList(listParams)))
    16             {
    17                 if (reader.HasRows)
    18                 {
    19                     list = new List<T>();
    20                     while (reader.Read())
    21                     {
    22                         T t = new T();
    23 
    24                         PropertyInfo[] propertys = t.GetType().GetProperties();
    25 
    26                         foreach (PropertyInfo pi in propertys)
    27                         {
    28                             tempName = pi.Name;
    29 
    30                             //for (int intField = 0; intField < reader.FieldCount; intField++)
    31                             //{//遍历该列名是否存在
    32                             //}
    33 
    34                             if (readerExists(reader, tempName))
    35                             {
    36                                 if (!pi.CanWrite)
    37                                 {
    38                                     continue;
    39                                 }
    40                                 var value = reader[tempName];
    41 
    42                                 if (value != DBNull.Value)
    43                                 {
    44                                     pi.SetValue(t, value, null);
    45                                 }
    46 
    47                             }
    48 
    49                         }
    50 
    51                         list.Add(t);
    52 
    53                     }
    54                     return list;
    55                 }
    56             }
    57             return null;
    58         }

    作者:dasihg

    转载:http://blog.csdn.net/dasihg/article/details/8943811

  • 相关阅读:
    iOS 的 Block 的使用
    iOS 的Could not find Developer Disk Image错误
    iOS 面试
    iOS 开发工具——统计Crash的工具Crashlytics
    iOS 的 Foundation 框架
    iOS 页面之间的传值总结
    iOS 常用四种数据存储方式
    iOS 的 Delegate Notification KVO
    iOS 的 Delegate 设计模式 及 自定义代理
    iOS 的 NSNumber(对基本数据类型) & NSValue(对结构体) 的装箱
  • 原文地址:https://www.cnblogs.com/luyuwei/p/4506449.html
Copyright © 2020-2023  润新知