public interface IMultiple {
        string GetName ();
    }

    public class ImplementationOne : IMultiple {
        public string GetName () {
            return "Abolfazl Roshanzamir";
        }
    }

    public class ImplementationTwo : IMultiple {
        public string GetName () {
            return "َAndy Madadian";
        }
    }

private readonly Func<string, IMultiple> _serviceAccessor;

public HomeController (Func<string, IMultiple> serviceAccessor) {
     this._serviceAccessor = serviceAccessor;
}
public IActionResult Index () {
    var implementOne = this._serviceAccessor ("A").GetName (); // Abolfazl Roshanzamir 
    var implementTwo = this._serviceAccessor ("B").GetName (); // Andy Madadian 
    return View ();
}

Error1The type or namespace name 'PdfReportSamples' could not be found (are you missing a using directive or an assembly reference?)...\pdfreport6797\Samples\WebAppTests\Default.aspx.cs37WebAppTests

Error2The type or namespace name 'PdfReportSamples' could not be found (are you missing a using directive or an assembly reference?)...\pdfreport26797\Samples\WpfAppTests\MainWindow.xaml.cs27WpfAppTests

Error3The type or namespace name 'PdfReportSamples' could not be found (are you missing a using directive or an assembly reference?)...\pdfreport26797\Samples\WindowsFormsAppTests\Form1.cs27WindowsFormsAppTests

Warning4The primary reference "...\pdfreport26797\Samples\PdfReportSamples\bin\Debug\PdfReportSamples.dll" could not be resolved because it has an indirect dependency on the framework assembly "System.Windows.Forms.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v3.5". To resolve this problem, either remove the reference "...\pdfreport-26797\Samples\PdfReportSamples\bin\Debug\PdfReportSamples.dll" or retarget your application to a framework version which contains "System.Windows.Forms.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35".WindowsFormsAppTests

   using SQLDMO;
   using System.Collections.Generic;

   public static List<string> GetSQLServersList2()
   {
       List<string> result = new List<string>();
       ApplicationClass sqlApp = new ApplicationClass();
       NameList lst = sqlApp.ListAvailableSQLServers();
       for (int i = 1; i <= lst.Count; i++)
           result.Add(lst.Item(i));
       lst = null;
       sqlApp = null;

       return result;

   }

using System.Collections.Generic;
using System.Data;
using System.Data.Sql;

public class CListServers
{
   public static List<string> GetSQLServersList()
   {
       List<string> result = new List<string>();

       // Retrieve the enumerator instance and then the data.
       var instance = SqlDataSourceEnumerator.Instance;
       var table = instance.GetDataSources();

       // Display the contents of the table.
       foreach (DataRow row in table.Rows)
       {
           result.Add(string.Format("{0}\\{1}", row[0], row[1]));
       }

       return result;
   }
}

using System.Collections.Generic;
using System.Data;
using Microsoft.SqlServer.Management.Smo;

public class CListServers
{
   public static List<string> GetSQLServersListSMO()
   {
       List<string> result = new List<string>();
       DataTable dt = SmoApplication.EnumAvailableSqlServers(false);
       if (dt.Rows.Count > 0)
       {
           foreach (DataRow dr in dt.Rows)
           {
               result.Add(dr["Name"].ToString());
           }
       }
       return result;
   }
}