C# 利用反射方便取得DbDataReader里的值

概述

在我以前做项目时,读DbDataReder里的值时都会用Reader.Read()然后根据名字来逐个读出.自从学会利用反射来读后,一切变得很容易.

以前的做法

定义一个Entity

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public class FileInformationModel  {     #region Public Property       /// <summary>     /// Gets and sets the file ID     /// </summary>     public string FileID { get; set; }       /// <summary>     /// Gets and sets the file name     /// </summary>     public string FileName { get; set; }       /// <summary>     /// Gets and sets the file save type     /// </summary>     public int? FileSaveType { get; set; }       /// <summary>     /// Gets and sets the file url     /// </summary>     public string FileUrl { get; set; }       /// <summary>     /// Gets and sets the file is new     /// </summary>     public bool? IsNew { get; set; }       /// <summary>     /// Gets and sets the file last access time     /// </summary>     public DateTime? LastAccessTime { get; set; }       /// <summary>     /// Gets and sets the file modity time     /// </summary>     public DateTime? ModifyTime { get; set; }       /// <summary>     /// Gets and sets the file version     /// </summary>     public int? Version { get; set; }       /// <summary>     /// Gets and sets the file content owner     /// </summary>     public string ContentOwner { get; set; }       /// <summary>     /// Gets and sets the file content type     /// </summary>     public string ContentType { get; set; }       /// <summary>     /// Gets and sets the file create date time     /// </summary>     public DateTime? CreateTime { get; set; }       /// <summary>     /// Gets and sets the file access control     /// </summary>     public string FileAccessControl { get; set; }       /// <summary>     /// Gets and sets the file from     /// </summary>     public string FileFrom { get; set; }       #endregion }

 

然后读取DbDataReader

 

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/// <summary> /// Execute reader by store procedure and parameter list /// </summary> /// <param name="cmdText">store procedure</param> /// <param name="parameters">parameter list</param> /// <returns>data reader</returns> public DbDataReader ExecuteReader(string cmdText, List<DbParameter> parameters,out DbConnection conn) {     lock (lockObject)     {           conn = new MySqlConnection(ConnectionString);         MySqlCommand command = new MySqlCommand();         PrepareCommand(command, conn, cmdText, parameters);         MySqlDataReader mySqlDataReader = command.ExecuteReader();         return mySqlDataReader;     } }

 

 

然后再如此读出数据

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/// <summary> /// Query FileInformationModel entity list by FileInformationModel entity /// </summary> /// <param name="entity">FileInformationModel entity</param> /// <returns>FileInformationModel entity list</returns> public List<FileInformationModel> Query(FileInformationModel entity) {    DbConnection conn;     var result =         ConvertDataReaderToList(DBHelp.ExecuteReader(Constants.spSelectFileInformationByCondition,                                                      GetParameters(entity),out conn));    ContentHelp.CloseConnection(conn);    return result; }   /// <summary> /// Convert data reader to FileInformationModel entity list /// </summary> /// <param name="reader">Db DataReader</param> /// <returns>FileInformationModel entity list</returns> private List<FileInformationModel> ConvertDataReaderToList(DbDataReader reader) {     List<FileInformationModel> fileInformationList = new List<FileInformationModel>();     using (reader)     {         while (reader.Read())         {             FileInformationModel entity = new FileInformationModel();             entity.ContentType = ContentHelp.GetObjectToString(reader["ConntentType"]);             entity.ContentOwner = ContentHelp.GetObjectToString(reader["ContentOwner"]);             entity.CreateTime = ContentHelp.GetObjectToDateTime(reader["CreateTime"]);             entity.FileAccessControl = ContentHelp.GetObjectToString(reader["FileAccessControl"]);             entity.FileFrom = ContentHelp.GetObjectToString(reader["FileFrom"]);             if (ContentHelp.GetObjectToString(reader["IsNew"]) != null)                 entity.IsNew = Convert.ToBoolean(ContentHelp.GetObjectToInt(reader["IsNew"]));             entity.FileName = ContentHelp.GetObjectToString(reader["FileName"]);             entity.FileSaveType = ContentHelp.GetObjectToInt(reader["FileSaveType"]);             entity.FileUrl = ContentHelp.GetObjectToString(reader["FileUrl"]);             entity.FileID = ContentHelp.GetObjectToString(reader["FileID"]);             entity.LastAccessTime = ContentHelp.GetObjectToDateTime(reader["LastAccessTime"]);             entity.ModifyTime = ContentHelp.GetObjectToDateTime(reader["ModifyTime"]);             entity.Version = ContentHelp.GetObjectToInt(reader["Version"]);             fileInformationList.Add(entity);         }     }     return fileInformationList; }

 

 

利用反射后,一切变得很容易.

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/// <summary> /// Execute reader by store procedure and parameter list /// </summary> /// <param name="cmdText">store procedure</param> /// <param name="parameters">parameter list</param> /// <returns>data reader</returns> public List<T> ReadEntityList<T>(string cmdText, List<DbParameter> parameters) where T : new() {     lock (lockObject)     {         using (MySqlConnection conn = new MySqlConnection(ConnectionString))         {             using (MySqlCommand command = new MySqlCommand())             {                 PrepareCommand(command, conn, cmdText, parameters);                 MySqlDataReader mySqlDataReader = command.ExecuteReader();                 return ReadEntityListByReader<T>(mySqlDataReader);             }         }     } }   /// <summary> /// Read entity list by reader /// </summary> /// <typeparam name="T">entity</typeparam> /// <param name="reader">data reader</param> /// <returns>entity</returns> private List<T> ReadEntityListByReader<T>(MySqlDataReader reader) where T : new() {     List<T> listT = new List<T>();     using (reader)     {         while (reader.Read())         {             T inst = new T();             foreach (var pi in typeof (T).GetProperties(BindingFlags.Instance | BindingFlags.Public))             {                 var obj = new object();                 try                 {                     obj = reader[pi.Name];                 }                 catch (Exception ex)                 {                     continue;                 }                   if (obj == DBNull.Value || obj == null)                     continue;                 var si = pi.GetSetMethod();                 if (si == null)                     continue;                 pi.SetValue(inst, obj, null);             }             listT.Add(inst);         }     }     return listT; }

 

 

然后再这样取出来

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/// <summary> /// Query FileInformationModel entity list by FileInformationModel entity /// </summary> /// <param name="entity">FileInformationModel entity</param> /// <returns>FileInformationModel entity list</returns> public List<FileInformationModel> Query(FileInformationModel entity) {     return DBHelp.ReadEntityList<FileInformationModel>(Constants.spSelectFileInformationByCondition,                                                        GetParameters(entity)); }

 

 

用好反射,让Coding变得更容易.

 

 

 

 

作者：spring yang

出处：http://www.cnblogs.com/springyangwc/

本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。