我使用的是 EF 4.3.1,我已经覆盖了上下文中的 SaveChanges(),这样我就可以获得对象及其状态的列表,并在我的审计日志表中创建条目。我需要将记录的 ID 存储在审计日志表中,以便我对它有一个引用。这是插入记录时的一个问题,因为在保存之前我无权访问该 ID。有什么方法可以在那时获取 ID 吗?
public override int SaveChanges()
{
ChangeTracker.DetectChanges();
var objectStateManager = ((IObjectContextAdapter)this).ObjectContext.ObjectStateManager;
var modifiedAuditableEntities = objectStateManager.GetObjectStateEntries(EntityState.Modified | EntityState.Added).Where(e => (IAuditable)e.Entity != null);
foreach (var entry in modifiedAuditableEntities)
{
var entity = (IAuditable)entry.Entity;
if (entity != null)
{
switch (entry.State)
{
case EntityState.Added:
entity.IsAdded = true;
break;
case EntityState.Deleted:
entity.IsDeleted = true;
break;
case EntityState.Modified:
entity.IsModified = true;
break;
}
this.EntitySet<AuditLogEntry>().Add(this.auditLogService.CreateAuditLogEntryForEntity((IAuditable)entry.Entity));
}
return base.SaveChanges();
}
最佳答案
如果您的目标是同时创建您的保存和审计日志,您可以将其包装在一个事务范围内,这样您的方法就是原子的。
public override int SaveChanges()
{
ChangeTracker.DetectChanges();
using (var scope = new TransactionScope())
{
var objectStateManager = ((IObjectContextAdapter) this).ObjectContext.ObjectStateManager;
var modifiedAuditableEntities =
objectStateManager.GetObjectStateEntries(EntityState.Modified | EntityState.Added).Where(
e => (IAuditable) e.Entity != null);
var result = base.SaveChanges();
foreach (var entry in modifiedAuditableEntities)
{
var entity = (IAuditable) entry.Entity;
if (entity != null)
{
switch (entry.State)
{
case EntityState.Added:
entity.IsAdded = true;
break;
case EntityState.Deleted:
entity.IsDeleted = true;
break;
case EntityState.Modified:
entity.IsModified = true;
break;
}
this.EntitySet<AuditLogEntry>().Add(
this.auditLogService.CreateAuditLogEntryForEntity((IAuditable) entry.Entity));
}
}
base.SaveChanges();
scope.Complete();
return result;
}
}
关于entity-framework - 在调用 SaveChanges() 之前添加的实体的访问 ID,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12933960/