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
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
/// <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
/// <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.
/// <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
/// <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.
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推荐下，万分谢谢.
作者：spring yang
出处：http://www.cnblogs.com/springyangwc/
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