.net 根据匿名类生成实体类，根据datatable生成实体类,根据sql生成实体类

在开发中可能会遇到这几种情况

1、EF或LINQ查询出来的匿名对象在其它地方调用不方便，又懒的手动建实体类

2、通过datatable反射实体需要先建一个类，头痛

3、通过SQL语句返回的实体也需要先建一个类 ，头痛

4、如果通过代码生成器要写模版，需要安装或者不想生成一堆不用的类

为了解决上面的不便之处，我封装了一个实体生成类，可以扔到程序里面任意调用

封装类：

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：实体生成类    /// ** 创始时间：2015-4-17    /// ** 修改时间：-    /// ** 作者：sunkaixuan    /// ** QQ：610262374 欢迎交流,共同提高 ,命名语法等写的不好的地方欢迎大家的给出宝贵建议    /// </summary>    public class ClassGenerating    {        /// <summary>        /// 根据匿名类获取实体类的字符串        /// </summary>        /// <param name="entity">匿名对象</param>        /// <param name="className">生成的类名</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>        /// 根据DataTable获取实体类的字符串        /// </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>        ///  根据SQL语句获取实体类的字符串        /// </summary>        /// <param name="sql">SQL语句</param>        /// <param name="className">生成的类名</param>        /// <param name="server">服务名</param>        /// <param name="database">数据库名称</param>        /// <param name="uid">账号</param>        /// <param name="pwd">密码</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>        ///  根据SQL语句获取实体类的字符串        /// </summary>        /// <param name="sql">SQL语句</param>        /// <param name="className">生成的类名</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>        /// 匹配类型        /// </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;        }    }}

调用如下：

           //通过匿名对象生成实体类            var dynamicObj = new { id = 1, name = "小名", entity = new enityt1() };           //注意：只能是单个实体不能传入 List<T> ,集合需要   List[0]            string classCode = ClassGenerating.DynamicToClass(dynamicObj, "classDynamic");            //通过datatable生成实体类            DataTable dt = new DataTable();            dt.Columns.Add("Id", typeof(int));            dt.Columns.Add("Name");            classCode = ClassGenerating.DataTableToClass(dt, "classTatabale");            //通过sql语句生成实体类            classCode = ClassGenerating.SqlToClass("select * from note", "Note", "127.0.0.1", "MyWork", "sa", "sasa");             classCode = ClassGenerating.SqlToClass("select * from dbo.accessoriesDetail", "AccessoriesDetail", "NFDEntities");//通过 config connstring名称

然后在调试状态把你需要的结果CTRL+C 然后去新建一个类CTRL+V