Getting a random UserProfile In SharePoint 2010 - sharepoint

Question

I am trying to retrieve a random number of users from the UserProfileManager.
But I am encountering errors when deploying to the live servers. I can't seem to see what is causing the error. My code is below:
for (int i = 0; i < NumberOfUserLimit; i++)
{
UserProfile up = profileManager.GetUserProfile(random.Next(1, NumberOfUserLimit));
if (up["FirstName"] != null && up["FirstName"].Value != null && !String.IsNullOrEmpty(up["FirstName"].Value.ToString()))
{
DataRow drUserProfile;
drUserProfile = dtUserProfile.NewRow();
drUserProfile["DisplayName"] = up.DisplayName;
drUserProfile["FirstName"] = up["FirstName"].Value;
drUserProfile["LastName"] = up["LastName"].Value;
drUserProfile["Department"] = up["Department"].Value;
drUserProfile["Location"] = up["SPS-Location"].Value;
drUserProfile["HireDate"] = up["SPS-HireDate"].Value;
drUserProfile["ContactNumber"] = up["Office"].Value;
if (up["PictureURL"] != null && up["PictureURL"].Value != null && !String.IsNullOrEmpty(up["PictureURL"].Value.ToString()))
{
string cleanAccountName = up["AccountName"].Value.ToString().Replace(#"\", "_");
string pictureUrl = String.Format("https://my.someintranet.com/User Photos/Profile Pictures/{0}_MThumb.jpg", cleanAccountName);
drUserProfile["Image"] = pictureUrl;
}
else
{
drUserProfile["Image"] = "~/_layouts/images/O14_person_placeHolder_96.png";
}
drUserProfile["MySiteUrl"] = up.PublicUrl;
dtUserProfile.Rows.Add(drUserProfile);
}
}
My code works when I apply a simple foreach to my code above instead of the "for loop":
foreach (UserProfile up in profileManager)
Which proves I can return userprofiles.
Any help is appreciated.

Answer 1

profileManager.GetUserProfile(long recordId)
expects a recordId from userprofile table. It is not an index, so you cannot use "random".
If you want to check RecordId, you can take a look at SQL tables of ProfileDB. Table "UserProfile_Full" has MasterRecordId column. Your parameter in GetUserProfile has to match of the user profile's MasterRecordId.
you can use the following code to get your random profiles:
IEnumerator profiles = profileManager.GetEnumerator();
int index = new Random().Next(1, 100);
while (index >= 0 && profiles.MoveNext())
index--;
UserProfile currentProfile = (UserProfile)profiles.Current

Answer 2

Code that handles Random better
public class TestClass
{
private random = new Random();
private long totalNumberOfProfiles; //ProfileManager.Count not always returns count correctly
public TestClass()
{
//this does not have to be in constructor but point is to have it cached (reasonably)
IEnumerator profiles = profileManager.GetEnumerator();
long counter = 0;
while (profiles.MoveNext())
counter++;
this.totalNumberOfProfiles = counter;
}
public fillInDataSet()
{
//something is here...
IEnumerator profiles = profileManager.GetEnumerator();
int index = random.Next(1, totalNumberOfProfiles);
while (index >= 0 && profiles.MoveNext())
index--;
UserProfile currentProfile = (UserProfile)profiles.Current
//something is here...
}
}