关于EntityFramework4.x/5.0只更新某部分字段的问题

因为4.x/5.0的context都采用了继承DbContext,但DbContext不提供修改字段状态的相关操作方法,可是实现了IObjectContextAdapter接口,我们可以从这里拿到ObjectContext,这样一切都好办了.我们可以如下操作

public int Update(E entity, string[] propertys)
        {
            int changeCount = 0;
            using(TransactionScope transaction = new TransactionScope (TransactionScopeOption.Required))
            {
                using (YzOASysEntities context = new YzOASysEntities())
                {
                    context.Set<E>().Attach(entity);
                    
                    IObjectContextAdapter objectContextAdatper = context;
                    ObjectContext objectContext = objectContextAdatper.ObjectContext;
                    ObjectStateEntry ose = objectContext.ObjectStateManager.GetObjectStateEntry(entity);
                    foreach (string property in propertys)
                    {
                        ose.SetModifiedProperty(property);
                    }

                    if (context.Entry<E>(entity).State == EntityState.Unchanged)
                        context.Entry<E>(entity).State = EntityState.Modified;
                    changeCount = context.SaveChanges();
                    if (changeCount > 0)
                        transaction.Complete();
                }
            }
            return changeCount;
            
        }

其实设不设置State是Modified都没问题.因为上面已经把状态给同步了.