ASP.NET中實現根據匿名類、datatable、sql產生實體類_實用技巧

在開發中可能會遇到這幾種情況：

1、EF或LINQ查詢出來的匿名對象在其它地方調用不方便，又懶的手動建實體類

2、通過datatable反射實體需要先建一個類 ，頭痛

3、通過SQL語句返回的實體也需要先建一個類 ，頭痛

4、如果通過代碼產生器要寫模版，需要安裝或者不想產生一堆不用的類 
 
為瞭解決上面的不便之處，我封裝了一個實體產生類，可以扔到程式裡面任意調用

封裝類：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Data;using System.Data.SqlClient;using System.Text.RegularExpressions; namespace SyntacticSugar{  /// <summary>  /// ** 描述：實體產生類  /// ** 創始時間：2015-4-17  /// ** 修改時間：-  /// ** 作者：sunkaixuan  /// ** qq：610262374 歡迎交流,共同提高 ,命名文法等寫的不好的地方歡迎大家的給出寶貴建議  /// </summary>  public class ClassGenerating  {    /// <summary>    /// 根據匿名類擷取實體類的字串    /// </summary>    /// <param name="entity">匿名對象</param>    /// <param name="className">產生的類名</param>    /// <returns></returns>    public static string DynamicToClass(object entity, string className)    {      StringBuilder reval = new StringBuilder();      StringBuilder propertiesValue = new StringBuilder();      var propertiesObj = entity.GetType().GetProperties();      string replaceGuid = Guid.NewGuid().ToString();      string nullable = string.Empty;      foreach (var r in propertiesObj)      {         var type = r.PropertyType;        if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))        {          type = type.GetGenericArguments()[0];          nullable = "?";        }        if (!type.Namespace.Contains("System.Collections.Generic"))        {          propertiesValue.AppendLine();          string typeName = ChangeType(type);          propertiesValue.AppendFormat("public {0}{3} {1} {2}", typeName, r.Name, "{get;set;}", nullable);          propertiesValue.AppendLine();        }      }       reval.AppendFormat(@"         public class {0}{{            {1}         }}      ", className, propertiesValue);        return reval.ToString();    }      /// <summary>    /// 根據DataTable擷取實體類的字串    /// </summary>    /// <param name="sql"></param>    /// <param name="className"></param>    /// <returns></returns>    public static string DataTableToClass(DataTable dt, string className)    {      StringBuilder reval = new StringBuilder();      StringBuilder propertiesValue = new StringBuilder();      string replaceGuid = Guid.NewGuid().ToString();      foreach (DataColumn r in dt.Columns)      {        propertiesValue.AppendLine();        string typeName = ChangeType(r.DataType);        propertiesValue.AppendFormat("public {0} {1} {2}", typeName, r.ColumnName, "{get;set;}");        propertiesValue.AppendLine();      }      reval.AppendFormat(@"         public class {0}{{            {1}         }}      ", className, propertiesValue);        return reval.ToString();    }     /// <summary>    /// 根據SQL語句擷取實體類的字串    /// </summary>    /// <param name="sql">SQL語句</param>    /// <param name="className">產生的類名</param>    /// <param name="server">服務名</param>    /// <param name="database">資料庫名稱</param>    /// <param name="uid">帳號</param>    /// <param name="pwd">密碼</param>    /// <returns></returns>    public static string SqlToClass(string sql, string className, string server, string database, string uid, string pwd)    {      using (SqlConnection conn = new SqlConnection(string.Format("server={0};uid={2};pwd={3};database={1}", server, database, uid, pwd)))      {        SqlCommand command = new SqlCommand();        command.Connection = conn;        command.CommandText = sql;        DataTable dt = new DataTable();        SqlDataAdapter sad = new SqlDataAdapter(command);        sad.Fill(dt);        var reval = DataTableToClass(dt, className);        return reval;      }    }    /// <summary>    /// 根據SQL語句擷取實體類的字串    /// </summary>    /// <param name="sql">SQL語句</param>    /// <param name="className">產生的類名</param>    /// <param name="connName">webconfig的connectionStrings name</param>    /// <returns></returns>    public static string SqlToClass(string sql, string className, string connName)    {      string connstr = System.Configuration.ConfigurationManager.ConnectionStrings[connName].ToString();      if (connstr.Contains("metadata"))//ef        connstr = Regex.Match(connstr, @"connection string\=""(.+)""").Groups[1].Value;      using (SqlConnection conn = new SqlConnection(connstr))      {        SqlCommand command = new SqlCommand();        command.Connection = conn;        command.CommandText = sql;        DataTable dt = new DataTable();        SqlDataAdapter sad = new SqlDataAdapter(command);        sad.Fill(dt);        var reval = DataTableToClass(dt, className);        return reval;      }    }    /// <summary>    /// 匹配類型    /// </summary>    /// <param name="type"></param>    /// <returns></returns>    private static string ChangeType(Type type)    {      string typeName = type.Name;      switch (typeName)      {        case "Int32": typeName = "int"; break;        case "String": typeName = "string"; break;      }      return typeName;    }  }}

調用如下：

//通過匿名對象產生實體類      var dynamicObj = new { id = 1, name = "小名", entity = new enityt1() };      //注意：只能是單個實體不能傳入 List<T> ,集合需要  List[0]      string classCode = ClassGenerating.DynamicToClass(dynamicObj, "classDynamic");      //通過datatable產生實體類      DataTable dt = new DataTable();      dt.Columns.Add("Id", typeof(int));      dt.Columns.Add("Name");      classCode = ClassGenerating.DataTableToClass(dt, "classTatabale");      //通過sql語句產生實體類      classCode = ClassGenerating.SqlToClass("select * from note", "Note", "127.0.0.1", "MyWork", "sa", "sasa");       classCode = ClassGenerating.SqlToClass("select * from dbo.AccessoriesDetail", "AccessoriesDetail", "NFDEntities");//通過 config connstring名稱

然後在調試狀態把你需要的結果CTRL+C 然後去建立一個類CTRL+V