Linq实体类的设计（解决了复合查询的问题，同时解决了LINQ上下文缓存问题）
<div id="cnblogs_post_body">文章中解决的问题：１ Linq to SQL不支持返回显示实体问题２ 解决了实体中导航属性为集合时类型转换错误的问题
实体的设计：
/// <summary>/// Linq原-生ú态类à型í的派é生ú类à，用来′临ù时±保￡存结á果集ˉ/// </summary>public class WebManageUsers_Ext : WebManageUsers { }/// <summary>/// 对Linq原-生ú态类à型í的扩展1/// </summary>public partial class WebManageUsers : EntityBase{ /// <summary> /// 实μ体集ˉ合：o导航属性为a集ˉ合时±，不能ü直±接ó写′为aList，它ü会á有D类à型í转a换错í误ó，必须是IEnumerable接ó口ú类à型í /// </summary> public IEnumerable<WebManageUser_WebManageRoles> WebManageUser_WebManageRoles_Extend { get; set; } /// <summary> /// 实μ体 /// </summary> public WebDepartments WebDepartments_Extend { get; set; } /// <summary> /// 统3一主÷键ü /// </summary> public override object[] PrimaryKey { get { return new object[] { this.ManageUserID }; } } /// <summary> /// 建¨立￠类à型í的对象ó时±，自动ˉ执′行D的代ú码逻辑- /// </summary> partial void OnCreated() { base.IsRealDeleted = false;//假ù删除y base.Initialization();//基ù类à的某3些属性初始化ˉ this.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(base.PropertyChangedEvent);//初始实μ体时±，先è订阅列D修T改的事件t }}而在进行进行复合查询时，我们可以这样来写：var linq = (from data in iWebManageUsersRepository.GetModel() join data2 in iWebDepartmentsRepository.GetModel() on data.DepartmentID equals data2.DepartmentID join data3 in iWebManageUser_WebManageRolesRepository.GetDetailModel() on data.ManageUserID equals data3.ManageUserID into list select new WebManageUsers_Ext { ManageUserID = data.ManageUserID, LoginName = data.LoginName, Password = data.Password, RealName = data.RealName, Gender = data.Gender, Phone = data.Phone, Mobile = data.Mobile, Email = data.Email, QQ = data.QQ, MSN = data.MSN, Rtx = data.Rtx, Birthday = data.Birthday, Description = data.Description, DepartmentID = data.DepartmentID, CreateDate = data.CreateDate, UpdateDate = data.UpdateDate, Operator = data.Operator, Status = data.Status, WebDepartments_Extend = data2, WebManageUser_WebManageRoles_Extend = list.Cast<WebManageUser_WebManageRoles>(), AvatarUrl = data.AvatarUrl, });在实体查询时，显式的返回了结果集，这样做的好处就是可以去除ＬＩＮＱ所带来的缓存问题下面是将用户及角色信息输出：linq.ToList().ForEach(i => { if (i.WebManageUser_WebManageRoles_Extend != null && i.WebManageUser_WebManageRoles_Extend.Count() > 0) i.WebManageUser_WebManageRoles_Extend.ToList().ForEach(j => Console.WriteLine(j.WebManageRoles_Extend.RoleName + j.WebManageUsers_Extend.RealName)); });看似简单的知识，事实上它困扰了我很长时间，可能也困扰了您很长时间吧，没关系，今天咱们终于把它解决了。
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