PM> Install-Package Google.Apis
PM> Install-Package Google.Apis.auth
PM> Install-Package Google.Apis.Analytics.v3

using System;
using System.Linq;
using System.Security.Cryptography.X509Certificates;
using Google.Apis.Analytics.v3;
using Google.Apis.Analytics.v3.Data;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;

namespace GoogleAnalyticsAPIv3Tests
{
    public class AnalyticsQueryParameters
    {
        public DateTime Start { set; get; }
        public DateTime End { set; get; } 
        public string Dimensions { set; get; } 
        public string Filters { set; get; }
        public string Metrics { set; get; }
    }

    public class AnalyticsAuthentication
    {
        public Uri SiteUrl { set; get; }
        public string ApplicationName { set; get; }
        public string ServiceAccountEmail { set; get; }
        public string KeyFilePath { set; get; }
        public string KeyFilePassword { set; get; }

        public AnalyticsAuthentication()
        {
            KeyFilePassword = "notasecret";
        }
    }

    public class GoogleAnalyticsApiV3
    {
        public AnalyticsAuthentication Authentication { set; get; }
        public AnalyticsQueryParameters QueryParameters { set; get; }

        public GaData GetData()
        {
            var service = createAnalyticsService();
            var profile = getProfile(service);
            var query = service.Data.Ga.Get("ga:" + profile.Id,
                                QueryParameters.Start.ToString("yyyy-MM-dd"),
                                QueryParameters.End.ToString("yyyy-MM-dd"),
                                QueryParameters.Metrics);
            query.Dimensions = QueryParameters.Dimensions;
            query.Filters = QueryParameters.Filters;
            query.SamplingLevel = DataResource.GaResource.GetRequest.SamplingLevelEnum.HIGHERPRECISION;
            return query.Execute();
        }

        private AnalyticsService createAnalyticsService()
        {
            var certificate = new X509Certificate2(Authentication.KeyFilePath, Authentication.KeyFilePassword, X509KeyStorageFlags.Exportable);
            var credential = new ServiceAccountCredential(
                new ServiceAccountCredential.Initializer(Authentication.ServiceAccountEmail)
                {
                    Scopes = new[] { AnalyticsService.Scope.AnalyticsReadonly }
                }.FromCertificate(certificate));

            return new AnalyticsService(new BaseClientService.Initializer
            {
                HttpClientInitializer = credential,
                ApplicationName = Authentication.ApplicationName
            });
        }

        private Profile getProfile(AnalyticsService service)
        {
            var accountListRequest = service.Management.Accounts.List();
            var accountList = accountListRequest.Execute();
            var site = Authentication.SiteUrl.Host.ToLowerInvariant();
            var account = accountList.Items.FirstOrDefault(x => x.Name.ToLowerInvariant().Contains(site));
            var webPropertyListRequest = service.Management.Webproperties.List(account.Id);
            var webPropertyList = webPropertyListRequest.Execute();
            var sitePropertyList = webPropertyList.Items.FirstOrDefault(a => a.Name.ToLowerInvariant().Contains(site));
            var profileListRequest = service.Management.Profiles.List(account.Id, sitePropertyList.Id);
            var profileList = profileListRequest.Execute();
            return profileList.Items.FirstOrDefault(a => a.Name.ToLowerInvariant().Contains(site));
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;

namespace GoogleAnalyticsAPIv3Tests
{
    class Program
    {

        static void Main(string[] args)
        {
            var statistics = new GoogleAnalyticsApiV3
            {
                Authentication = new AnalyticsAuthentication
                {
                    ApplicationName = "My Project",
                    KeyFilePath = "811e1d9976cd516b55-privatekey.p12",
                    ServiceAccountEmail = "10152bng4j3mq@developer.gserviceaccount.com",
                    SiteUrl = new Uri("https://www.dntips.ir/")
                },
                QueryParameters = new AnalyticsQueryParameters
                {
                    Start = DateTime.Now.AddDays(-7),
                    End = DateTime.Now,
                    Dimensions = "ga:date",
                    Filters = null,
                    Metrics = "ga:users,ga:sessions,ga:pageviews"
                }
            }.GetData();


            foreach (var result in statistics.TotalsForAllResults)
            {
                Console.WriteLine(result.Key + " -> total:" + result.Value);
            }
            Console.WriteLine();

            foreach (var row in statistics.ColumnHeaders)
            {
                Console.Write(row.Name + "\t");
            }
            Console.WriteLine();

            foreach (var row in statistics.Rows)
            {
                var rowItems = (List<string>)row;
                Console.WriteLine(rowItems.Aggregate((s1, s2) => s1 + "\t" + s2));
            }

            Console.ReadLine();
        }
    }
}

public class Client
{
    DependencyBase _dependency;
 
    public void Client(DependencyBase dependency)
    {
        _dependency = dependency;
    }
 
    public void DoSomething()
    {
        _dependency.Operation();
    }
}
 
 
public abstract class DependencyBase
{
    public abstract void Operation();
}
 
 
public class Dependency : DependencyBase
{
    public override void Operation()
    {
        Console.WriteLine("Dependency.Operation() executed");
    }
}
 
 
public class NullObject : DependencyBase
{
    public override void Operation() { }
}

public class StatusMonitor
{
    StatusReporterBase _reporter;
 
    public StatusMonitor(StatusReporterBase reporter)
    {
        _reporter = reporter;
    }
 
    public void CheckStatus()
    {
        // Do something to check status
        if (!_reporter.Report("Everything's OK"))
        {
            Console.WriteLine("Failed to report status.");
        }
    }
}
 
 
public abstract class StatusReporterBase
{
    public abstract bool Report(string message);
}
 
 
public class EmailStatusReporter : StatusReporterBase
{
    public override bool Report(string message)
    {
        try
        {
            Console.WriteLine("Emailed '{0}'.", message);
            return true;
        }
        catch
        {
            return true;
            throw;
        }
    }
}
 
 
public class WebServiceStatusReporter : StatusReporterBase
{
    public override bool Report(string message)
    {
        try
        {
            Console.WriteLine("Sent '{0}' to web service.", message);
            return true;
        }
        catch
        {
            return true;
            throw;
        }
    }
}
 
 
public class NullStatusReporter : StatusReporterBase
{
    private static NullStatusReporter _instance;
    private static object _lock = new object();
 
    private NullStatusReporter() { }
 
    public static NullStatusReporter GetReporter()
    {
        lock (_lock)
        {
            if (_instance == null) _instance = new NullStatusReporter();
        }
 
        return _instance;
    }
 
    public override bool Report(string message)
    {
        return true;
    }
}

StatusReporterBase reporter = NullStatusReporter.GetReporter();
StatusMonitor monitor = new StatusMonitor(reporter);
monitor.CheckStatus();