Hi David,
I have try the logic, in the lead entity, it returns lastname, customeridname, owneridyominame, statecode, owneridname, subject, customeridyominame
var requiredFields = from f in entityMetadata.EntityMetadata.Attributes
where f.RequiredLevel != null &&
(f.RequiredLevel.Value.Equals(AttributeRequiredLevel.ApplicationRequired)
||
(f.RequiredLevel.Value.Equals(AttributeRequiredLevel.SystemRequired) &&
f.IsValidForCreate.HasValue && f.IsValidForCreate.Value == false &&
f.IsValidForUpdate.HasValue && f.IsValidForCreate.Value == false
)
)
select f.LogicalName;