Entity Framework 6 实体某些字段根据模型状态进行自动更新内容
1.定义基础实体对象
public class BaseEntity { public int Id { get; set; } public DateTime? CreateTime { get; set; } public DateTime? UpdateTime { get; set; } public BaseEntity() { CreateTime = DateTime.Now; } }
2.定义业务实体对象
public class DictEntity:BaseEntity { /// <summary> /// 分组名称 /// </summary> [StringLength(20)] public string GroupName { get; set; } }
3.在DbContext类里重写SaveChanges()方法
public class DBContext : DbContext { public DBContext() : base("Name=ElectronicPrescriptionDB") { Database.SetInitializer(new DBInitializer()); } public DbSet<DictEntity> Dicts { get; set; }
public override int SaveChanges() { var selectedEntityList = ChangeTracker.Entries().Where(x => x.Entity is BaseEntity && x.State == EntityState.Modified); //可以加入cookie里面的username,比如:操作人,需扩展DateTimeEntity的属性。 //var userName = "MUKESH"; foreach (var entity in selectedEntityList) { ((BaseEntity)entity.Entity).UpdateTime = DateTime.Now; } return base.SaveChanges(); } }
之所以选择此方法,经过测试后最简便方法。其他还有:
public RepositoryContext() : base("ApiConn") { ((IObjectContextAdapter)this).ObjectContext.ObjectStateManager.ObjectStateManagerChanged += this.OnSaveChanges; }
在OnSaveChanges(object obj, CollectionChangeEventArgs args)里面去获取实体状态,根据实体状态进行更新对应数据。但是,每次触发实体都会触发该扩展方法。所以没选择。
终身学习,系统学习。