ASP.NET中实现根据匿名类、datatable、sql生成实体类

数据库  /  管理员 发布于 5年前   179

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