Setting 'print and export to excel' for some user using QMS API

[#1]

Hi all,

I wanna setting "print and export to excel" using QMS API. Below is the qmc settings, I can easily set the option to ALL, NONE, some users and groups. And all the settings are working.

Now I wanna set using QMS API, here is the c#  code. My question is : the first two fuction ( setExceltoUsers and setExceltoNone) work well, but the 3rd one ( setExceltoAll) doesn't work. What's wrong with my code? Thanks.

 public static void setExceltoUsers(string guid, params string[] userNames)
        {
            try
            {
                if (guid != null && userNames != null)
                {
                    QMSClient client = GetClient();
                    DocumentMetaData documnet = GetDocumentMetaData(guid);
                    documnet.Server.Access.ExportUsers = userNames;
                    documnet.Server.Access.Export = DocumentDownloadAccess.Restricted;
                    client.SaveDocumentMetaData(documnet);
                }
            }
            catch { }
        }
 public static void setExceltoNone(string guid)
        {
            try
            {
                if (guid != null)
                {
                    QMSClient client = GetClient();
                    DocumentMetaData documnet = GetDocumentMetaData(guid);
                    documnet.Server.Access.Export = DocumentDownloadAccess.None;
                    client.SaveDocumentMetaData(documnet);
                }
            }
            catch { }
        }
 public static void setExceltoAll(string guid)
        {
            try
            {
                if (guid != null)
                {
                    QMSClient client = GetClient();
                    DocumentMetaData documnet = GetDocumentMetaData(guid);
                    documnet.Server.Access.Export = DocumentDownloadAccess.All;
                    client.SaveDocumentMetaData(documnet);
                }
            }
            catch { }
        }

!