更新操作麻烦

Question

这是我的更新操作：

 public void etat(string id) 
    { 

      Models.J2VEntities entity = new Models.J2VEntities(); 

      Models.user model = (from p in entity.user 
           where p.iduser == id 
           select p).SingleOrDefault(); 

      model.IsActive = !(model.IsActive); 
      entity.user.AddObject(model); 
      entity.ObjectStateManager.ChangeObjectState(model, System.Data.EntityState.Modified); 
      entity.SaveChanges(); 
      RedirectToAction("Index", "Admin"); 
    } 

当我excutet我得到这个错误：

System.InvalidOperationException：具有相同键的对象已经存在于ObjectStateManager。现有对象处于Modified状态。如果在状态中添加对象，则可以将对象添加回ObjectStateManager。

在这一行：entity.user.AddObject(model);

Answer 1

Sloved以这种方式：

using (var entity = new Models.J2VEntities()) 
      { 
       Models.user model = (from p in entity.user 
            where p.iduser == id 
            select p).SingleOrDefault(); 
       model.IsActive = !(model.IsActive); 
       entity.user.ApplyCurrentValues(model); 
       entity.SaveChanges(); 
      } 

Answer 2

试试这个：

public void etat(string id){ 
using(var entity = new Models.J2VEntities()){ 
    Models.user model = (from p in entity.user 
          where p.iduser == id 
          select p).SingleOrDefault(); 
    model.IsActive = !(model.IsActive); 
    entity.user.Attach(model); 
    entity.Entry(model).State = EntityState.Modified; 
    entity.SaveChanges(); 
} 
} 

的using将确保您的连接设置和正确关闭，以确保你没有内存泄漏或不需要开连接。