无法更新对象，因为其密钥已存在

我有以下方法负责更新对象： -

private TMSEntities tms = new TMSEntities();
//code goes here...    
public void InsertOrUpdateServer(TMSServer server, string username,long assetid)
    {
        // code goes here
        }
        else
        {
            var auditinfo = IntiateAudit(tms.AuditActions.SingleOrDefault(a => a.Name.ToUpper() == "EDIT").ActionID,
            tms.TechnologyTypes.SingleOrDefault(a => a.Name.ToUpper() == "Server").AssetTypeID,
            username, server.ServerID);
            server.IT360SiteID = resource.SITEID.Value;
            tms.Entry(server).State = EntityState.Modified;
            InsertOrUpdateAudit(auditinfo);
        }
    }

但我得到以下错误： -

tms.Entry(server).State = EntityState.Modified;

ObjectStateManager中已存在具有相同键的对象 . ObjectStateManager无法使用相同的键跟踪多个对象 . 描述：执行当前Web请求期间发生未处理的异常 . 请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息 . 异常详细信息：System.InvalidOperationException：ObjectStateManager中已存在具有相同键的对象 . ObjectStateManager无法使用相同的键跟踪多个对象 . 来源错误：

虽然我只跟踪一个对象，但我怎么能解决这个问题呢？

UPDATE 我在我的方法中添加了以下内容： -

tms.Entry(server).CurrentValues.SetValues(server);

代替

tms.Entry(server).State = EntityState.Modified;

但我得到以下例外： -

无法为“TMSServer”类型的实体调用成员“CurrentValues”，因为该实体在上下文中不存在 . 要向上下文添加实体，请调用DbSet的Add或Attach方法 .

Second update:-

public Audit IntiateAudit(int actionId, int assettypeID, string username, int? technologyID)
        {


            TechnologyAudit ta = new TechnologyAudit();
            ta.ActionID = actionId;
            ta.AssetTypeID = assettypeID;  
            ta.DateTimeStart = DateTime.Now;
            ta.UserName = username;
            if (technologyID != null)
            {
                ta.TechnologyID = technologyID.Value;
            }

            return ta;


        }

＆

public void InsertOrUpdateAudit(Audit ta)
        {
            if (ta.ID == default(int))
            {
                // New entity
                ta.DateTimeEnd = DateTime.Now;
                tms.TechnologyAudits.Add(ta);

            }
            else
            {
                // Existing entity
                tms.Entry(ta).State = EntityState.Modified;
            }

＆

public partial class TechnologyType
    {
        public TechnologyType()
        {
            this.SecurityroleTypePermisions = new HashSet<SecurityroleTypePermision>();
            this.Technologies = new HashSet<Technology>();
            this.TechnologyAudits = new HashSet<TechnologyAudit>();
        }

        public int AssetTypeID { get; set; }
        public string Name { get; set; }

        public virtual ICollection<SecurityroleTypePermision> SecurityroleTypePermisions { get; set; }
        public virtual ICollection<Technology> Technologies { get; set; }
        public virtual ICollection<TechnologyAudit> TechnologyAudits { get; set; }
    }

＆

public partial class TMSServer
    {
        public TMSServer()
        {
            this.TMSServers1 = new HashSet<TMSServer>();
            this.TMSVirtualMachines = new HashSet<TMSVirtualMachine>();
        }

        public int TMSServerID { get; set; }
        public Nullable<int> ServerModelID { get; set; }
        public int DataCenterID { get; set; }
        public string ILOIP { get; set; }
        public int RackID { get; set; }
        public Nullable<int> StatusID { get; set; }
        public Nullable<int> BackUpStatusID { get; set; }
        public int RoleID { get; set; }
        public Nullable<int> OperatingSystemID { get; set; }
        public Nullable<int> VirtualCenterID { get; set; }
        public string Comment { get; set; }
        public byte[] timestamp { get; set; }
        public long IT360SiteID { get; set; }

        public virtual DataCenter DataCenter { get; set; }
        public virtual OperatingSystem OperatingSystem { get; set; }
        public virtual ServerModel ServerModel { get; set; }
        public virtual Technology Technology { get; set; }
        public virtual TechnologyBackUpStatu TechnologyBackUpStatu { get; set; }
        public virtual TechnologyRole TechnologyRole { get; set; }
        public virtual TechnologyStatu TechnologyStatu { get; set; }
        public virtual TMSRack TMSRack { get; set; }
        public virtual ICollection<TMSServer> TMSServers1 { get; set; }
        public virtual TMSServer TMSServer1 { get; set; }
        public virtual ICollection<TMSVirtualMachine> TMSVirtualMachines { get; set; }
    }
}        }

Third UPDATE

审计代码是： -

public TechnologyAudit IntiateTechnologyAudit(int actionId, int assettypeID, string username, int? technologyID)
        {


            TechnologyAudit ta = new TechnologyAudit();
            ta.ActionID = actionId;
            ta.AssetTypeID = assettypeID;  
            ta.DateTimeStart = DateTime.Now;
            ta.UserName = username;
            if (technologyID != null)
            {
                ta.TechnologyID = technologyID.Value;
            }

            return ta;


        }
        public void InsertOrUpdateTechnologyAudit(TechnologyAudit ta)
        {
            if (ta.ID == default(int))
            {
                // New entity
                ta.DateTimeEnd = DateTime.Now;
                tms.TechnologyAudits.Add(ta);

            }
            else
            {
                // Existing entity
                tms.Entry(ta).State = EntityState.Modified;
            }
        }