add multiple different items in List (distinct items)

Ritu

4y1kC#

Hi,

I have few list which get deistinct items now I want to add below list items in one common list

List tdata = new List()

but not able to add this.

List a = rosterExports.Select(x => x.id).Distinct().ToList();
List b = rosterExports.Select(x => x.name).Distinct().ToList();
List c = rosterExports.Select(x => x.fname).Distinct().ToList();
List d= rosterExports.Select(x => x.lname).Distinct().ToList();
List die = rosterExports.Select(x => x.gender).Distinct().ToList();
List f= rosterExports.Select(x => x.code).Distinct().ToList();
List k= rosterExports.Select(x => x.status).Distinct().ToList();
List l= rosterExports.Select(x => x.address).Distinct().ToList();
List m= rosterExports.Select(x => x.city).Distinct().ToList();
List n= rosterExports.Select(x => x.zip).Distinct().ToList();

please help.

thanks

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sachin Singh4y ago
Accepted answer
as your export method expects a list of RosterModel you can't pass an anonymous object to it. you need to explicitly override the equals method within the class to match the method signature.
public static void GetAlignRosterMemberTerritory()
        {
            string roster_member_terr_alnQuery = Environment.GetEnvironmentVariable("roster_member_terr_alnQuery");

            string currDate = GetDate();
            roster_member_terr_alnQuery = roster_member_terr_alnQuery.Replace(">", ">").Replace("#CurrentDate", currDate);

            string acessToken =
            System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            string RosterJSON = HTTPHelper.Get(,, acessToken);

            try
            {
                RosterExportModel exportModel = new RosterExportModel();
                exportModel.rosterExports = new List();

                List rosterExports = new List();


                AlignRoster alignRoster = Newtonsoft.Json.JsonConvert.DeserializeObject(RosterJSON);

                rosterExports = alignRoster.data.Select(rH => new RosterExport
                {
                    territory__aln_external_id__aln = rH.territory__alnr.data.FirstOrDefault().external_id__aln,
                    roster_member__aln_name__v = rH.roster_member__alnr.data.FirstOrDefault().name__v,
                    first_name__aln = rH.roster_member__alnr.data.FirstOrDefault().first_name__aln,
                    last_name__aln = rH.roster_member__alnr.data.FirstOrDefault().last_name__aln,
                    roster_nickname__c = rH.roster_nickname__c,

                }).Distinct().ToList();



     WriteCSV_AlignRoster_TerritoryTOS3(distinctList);
    }
public class RosterExport
    {
        public string territory__aln_external_id__aln { get; set; }
        public string roster_member__aln_name__v { get; set; }
        public string first_name__aln { get; set; }
        public string last_name__aln { get; set; }
        public string roster_nickname__c { get; set; }
       public override bool Equals(object obj)
        {
            // If the passed object is null
            if (obj == null)
            {
                return false;
            }
            if (!(obj is RosterExport)
            {
                return false;
            }
            return (this.territory__aln_external_id__aln == ((RosterExport)obj).territory__aln_external_id__aln)
                && (this.roster_member__aln_name__v == ((RosterExport)obj).roster_member__aln_name__v)
&& (this.roster_member__aln_name__v == ((RosterExport)obj).roster_member__aln_name__v)
&& (this.first_name__aln== ((RosterExport)obj).first_name__aln)
&& (this.last_name__aln== ((RosterExport)obj).last_name__aln)
&& (this.roster_nickname__c== ((RosterExport)obj).roster_nickname__c);
        }
        public override int GetHashCode()
        {
            return territory__aln_external_id__aln.GetHashCode() ^ roster_member__aln_name__v.GetHashCode();
        }
    }

    public class RosterExportModel
    {
        public List rosterExports { get; set; }

    }
Ritu4y ago
@Sachin Singh
I have the file for ur reference, please check
Sachin Singh4y ago
@Ritu Gupta,
It works and will always work, as I said when we project to anonymous type the hashcode and equals method of the respective class gets overridden so Distinct will produce the distinct result.
see,
it's working here
class Program
   {
       static void Main(string[] args)
       {
           Console.WriteLine();
           List m = new List
           {
               new RosterModel(){ Name="Sachin",code="sachin123"},
               new RosterModel(){ Name="Sachin",code="sachin123"},
               new RosterModel(){ Name="Sachin",code="sachin123"}
           };

           var distinctWontWork = m.Distinct();

           Console.WriteLine("without anonymous type ");
           foreach(var item in distinctWontWork)
           {
               Console.WriteLine(item.Name);
               Console.WriteLine(item.code);
           }
           var distinctM = m.Select(x => new { Name = x.Name, code = x.code }).Distinct();
           Console.WriteLine("-------------------");
           Console.WriteLine("with anonymous type");
           foreach (var item in distinctM)
           {
               Console.WriteLine(item.Name);
               Console.WriteLine(item.code);
           }
           Console.ReadLine();
       }
   }

   public class RosterModel
   {
       public string Name { get; set; }
       public string code { get; set; }
   }
as you can see below Distinct() doesn't work on reference types until we project the rest to a new anonymous type.
Ritu4y ago
already tried this solution but not getting distinct records
Sachin Singh4y ago
Then why are you not doing a single select with distinct
var res=rosterExports.Select(x =>
new {
a=x.id,
b=x.Name,
c=x.Gender
// so on
}
).Distinct().ToList();
when we project list to anonymous type (new {}) then equals and hascode of objects are overriden internally, so distinct start giving us distinct result.
Ritu4y ago
basically i am geeting data from api and store in excel file but I want distinct records and here rosterExports is a list type object of class RosterModel which contains variables.
Sachin Singh4y ago
Simply you can
a.Union(b).Union(c).Union(d).Union(e)
Union is very handy with linq.
Nitin Sontakke4y ago
Much nicer if you could please explain what is it that you want to achieve at the end.

I am seeing that you probably collecting data horizontally. What would be the purpose of such disconnected data and then trying to put it all together.

May be you could create a list of Object, but then again it is defeating the whole point of type safely and you will ultimately do a lot of casting.