Getting Null data from google adwords api - asp.net

Question

I want to fetch location details for all the ads from google adwords but I am getting null entries.I am not able to get any data from adwords api .Help me in That as according to my knowledge there is not problem with my code and I am not able to find any solution for that.My code that I have tried is written below.
public void GetLocationAds()
{
AdWordsUser user = new AdWordsUser();
{
try
{
int offset = 0;
// Create selector.
using (CampaignCriterionService campaignCriterionService =
(CampaignCriterionService)user.GetService(AdWordsService.v201809.CampaignCriterionService))
{
Selector selector = new Selector()
{
fields = new string[]
{
CampaignCriterion.Fields.CampaignId,
CampaignCriterion.Fields.CampaignCriterionStatus,
//Location.Fields.LocationName,
//Location.Fields.CriteriaType,
//Location.Fields.ParentLocations,
//LocationCriterion.Fields.CanonicalName,
//LocationCriterion.Fields.CountryCode,
CampaignCriterion.Fields.IsNegative,
},
// predicates = new Predicate[]
//{
// Predicate.Equals( "CriteriaType","LOCATION"),
//},
paging = Paging.Default,
ordering = new OrderBy[]
{
OrderBy.Asc( CampaignCriterion.Fields.CampaignId)
}
};
CampaignCriterionPage page = new CampaignCriterionPage();
do
{
// Get the ad groups.
page = campaignCriterionService.get(selector);
// Display the results.
if (page != null && page.entries != null)
{
int j = selector.paging.startIndex;
foreach (CampaignCriterion campaignCriterion in page.entries)
{
var campaignId = campaignCriterion.campaignId;
bool IsLocation = campaignCriterion.isNegative;
var CampaignCriterionType = campaignCriterion.CampaignCriterionType;
}
}
else
{
Console.Write("No campaignCriterion were found.");
}
selector.paging.IncreaseOffset();
}
while (selector.paging.startIndex < page.totalNumEntries);
}
}
catch (Exception ex)
{
}
}
}
Kindly help me in that.