/// <summary>
/// 编辑一个对象
/// </summary>
/// <param name="db">实体数据</param>
/// <param name="entity">将要编辑的一个对象</param>
/// <param name="isAttach">是否附加到数据库上下文</param>
public virtual T Edit(SysEntities db, T entity, bool isAttach = true)
{
if (isAttach)
{
db.Set <T>().Attach(entity);
}
db.Entry(entity).State = System.Data.Entity.EntityState.Modified;
return(entity);
}