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Assign string[] array field to another array field of same type c#

I have two classes defined in my solution
public class Registration {
[...]
public list<Account> Accounts {get; set;}
}
public class Account {
[...]
public string Code { get; set; }
public string Name { get; set; }
public string Address { get; set; }
}
In the web service that I am consuming, the following class definitions are available
public partial class VendReg {
[...]
private Payment_Details[] requestDetailsField;
[System.Xml.Serialization.XmlArrayItemAttribute(IsNullable=false)]
public Payment_Details[] RequestDetails {
get {
return this.requestDetailsField;
}
set {
this.requestDetailsField = value;
}
}
}
public partial class Payment_Details {
private string bk_CodeField;
private string bk_NameField;
private string bk_AddressField;
public string Bk_Code {
get {
return this.bk_CodeField;
}
set {
this.bk_CodeField = value;
}
}
public string Bk_Name {
get {
return this.bk_NameField;
}
set {
this.bk_NameField = value;
}
}
public string Bk_Address {
get {
return this.bk_AddressField;
}
set {
this.bk_AddressField = value;
}
}
}
I want to assign Account to Request Details which is an array of Payment_Details. I tried this code below
vendReg.RequestDetails = registration.Accounts.Cast<Payment_Details>().ToArray();
I got invalid cast exception: Unable to cast object of type 'Account' to type 'Payment_Details'
Please guide on what I am not doing right

You need to convert this yourself (or you can look into things like Automapper)
vendReg.RequestDetails = registration.Accounts.Select(acc =>
new Payment_Details {
Bk_Code = acc.Code,
Bk_Name = acc.Name,
Bk_Address = acc.Address
}).ToArray();

Type Casting Exception With Inheritance

Here is my code below. It gives me Casting exception problem at selIngs.Add(da). tried with the 2nd way. it still give me the same exception. I wonder where I am doing wrong? Once I implement the interface or inherit the base class it should be ok to treat child class as the same. Any idea please?
//1st way
public interface IngredientInterface
{
double Concentration { get; set; }
string DateCreated { get; set; }
string DevCode { get; set; }
}
public class IngredientData : INotifyPropertyChanged, IngredientInterface
{
public string GroupCode
{
get { return groupCode; }
set
{
groupCode = value;
}
}
public double Setpoint { get; set; }
public bool IsHighlighted { get; set; }
public double PPT { get; set; }
}
public class FormulaUploadViewModelData: IngredientData
{
//.....
}
public class FormulaUploadViewModel :INotifyPropertyChanged
{
public FormulaUploadViewModel()
{
selIngs = new List<FormulaUploadViewModelData>();
}
private void IngsUp()
{
List<IngredientData> someIngData = new List<IngredientData>();
foreach (FormulaUploadViewModelData da in someIngData)
{
selIngs.Add(da); //here gives me casting exception
}
}
}
//2nd way
public class FormulaUploadViewModelData: IngredientInterface
{
//.....
}
public class FormulaUploadViewModel :INotifyPropertyChanged
{
public FormulaUploadViewModel()
{
selIngs = new List<FormulaUploadViewModelData>();
}
private void IngsUp()
{
List<IngredientInterface> someIngData = new List<IngredientInterface>();
foreach (FormulaUploadViewModelData da in someIngData)
{
selIngs.Add(da); //here gives me casting exception
}
}
}

All FormulaUploadViewModelData are IngredientInterface. So this will work:
var ingredients = new List<IngredientInterface>();
ingredients.Add(new FormulaUploadViewModelData());
But the opposite does not work because not all IngredientInterface are FormulaUploadViewModelData which is what should follow from allowing:
var formulas = new
List<FormulaUploadViewModelData>();
formulas(someIngredientInterface);
Solution? Make sure the da you are adding is in fact a FormulaUploadViewModelData. There is quite a few ways to do it, to name a couple:
Pattern matching
foreach (var da in someInData)
if (da is FormulaUploadViewModelData formula)
selIngs.Add(formula)
Use Enumerable.OfType<> extension method
foreach (var formula in
someInData.OfType<FormulaUploadViewModelData>())
selIngs.Add(formula)
Etc.

C# Inheritance, new modifier and generics

I'm having a hard trying to find to correct approach to this :
My data structures :
public abstract class Flow
{
public virtual double Value { get; set; }
public virtual DateTime Time { get; set; }
}
public class InboundFlow : Flow
{
}
public class OutboundFlow : Flow
{
}
My business objects containing collections of these data structures
public abstract class Fluent
{
public virtual IList<Flow> FlowCollection { get; set; }
public virtual double InitialBaseflow { get; set; }
}
public class Affluent : Fluent
{
public new virtual IList<InboundFlow> FlowCollection { get; set; }
}
public class Effluent : Fluent
{
public new virtual IList<OutboundFlow> FlowCollection { get; set; }
}
The generic method I'm trying to use :
private static void FindInitialBaseflow<T>(ref T fluent) where T : Fluent
{
var linqFluent = fluent;
var flows = linqFluent.FlowCollection.ToList().FindAll(
flow =>
flow.Time >= SOME_DATE &&
flow.Time < SOME_OTHER_DATE);
var initialBaseflow = flows.Average(flow => flow.Value);
fluent.InitialBaseflow = Math.Round(initialBaseflow, 5);
}
My problem is that calling "linqfluent.FlowCollection" in the linq method calls for the base class Fluent's FlowCollection, which is null.
How can I force the use of the child's property instead? Thanks!

You need to make the collection within Fluent generic so that the classes that inherit from it can specify the type:
public class Fluent<T>
where T : Flow
{
public IList<T> FlowCollection { get; set; }
public double InitialBaseflow { get; set; }
}
Once you have that you don't even need sub classes of Flow, you can just make it concrete.
Your use of it would be easily modified to fit this model:
private static void FindInitialBaseflow<T>(Fluent<T> fluent)
where T : Flow
{
var linqFluent = fluent;
var flows = linqFluent.FlowCollection.Where(
flow =>
flow.Time >= SOME_DATE &&
flow.Time < SOME_OTHER_DATE);
var initialBaseflow = flows.Average(flow => flow.Value);
fluent.InitialBaseflow = Math.Round(initialBaseflow, 5);
}
Also note that since you're not setting fluent in this method, there is no need to pass it by reference. It's already a class, so it is itself a reference; mutations of the referenced object will be observed by the caller.

Generics are the wrong tool. You should using polymorphism to ensure the correct implementation is called based on the type.
For example:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
namespace ConsoleApp
{
public abstract class Flow
{
public virtual double Value { get { return new Random().Next() ; } }//these values are just for demonstration purposes
public virtual DateTime Time
{
get
{
return DateTime.MinValue.AddYears(1);
}
}
}
public class InboundFlow : Flow
{
}
public class OutboundFlow : Flow
{
}
public abstract class Fluent
{
IList<Flow> _flowCollection;
public virtual IList<Flow> FlowCollection
{
get { return _flowCollection; }
set { _flowCollection = value; }
}
private double _initialBaseflow;
public virtual double InitialBaseflow
{
get { return _initialBaseflow; }
set { _initialBaseflow = value; }
}
public Fluent()
{
FlowCollection = new List<Flow>();
}
}
public class Affluent : Fluent
{
//public new virtual IList<InboundFlow> FlowCollection { get; set; }//Keep the property polymorphic
public Affluent()
{
FlowCollection = new List<Flow>();
}
}
public class Effluent : Fluent
{
//public new virtual IList<OutboundFlow> FlowCollection { get; set; }
public Effluent()
{
FlowCollection = new List<Flow>();
}
}
class Program
{
public static DateTime SOME_DATE { get { return DateTime.MinValue; } }
public static DateTime SOME_OTHER_DATE { get { return DateTime.Now; } }
static void Main(string[] args)
{
var inbound = new InboundFlow();
var inbound2 = new InboundFlow();
var outbound = new OutboundFlow();
var a = new Affluent();
a.FlowCollection.Add(inbound);
a.FlowCollection.Add(inbound2);
FindInitialBaseflow(a);
}
private static void FindInitialBaseflow(Fluent fluent)
{
var linqFluent = fluent;
var flows = linqFluent.FlowCollection.ToList().FindAll(
flow =>
flow.Time >= SOME_DATE &&
flow.Time < SOME_OTHER_DATE);
var initialBaseflow = flows.Average(flow => flow.Value);
fluent.InitialBaseflow = Math.Round(initialBaseflow, 5);
}
}
}

TDD - Why does this Assert.AreSame pass?

I have a test method...
[TestMethod]
public void MainViewModel_PropertiesReflectDataEntityProperties()
{
// Arrange
var facilityDataEntity = MockRepository.GenerateStub<FacilityDataEntity>();
var shopOrderDataEntity = MockRepository.GenerateStub<ShopOrderDataEntity>();
// Act
MainViewModel mainViewModel = new MainViewModel(facilityDataEntity, shopOrderDataEntity);
// Assert
Assert.AreSame(facilityDataEntity.Value, mainViewModel.FacilityValue);
}
... and the test passes. However, I have not implemented the mapping of the DataEntity's properties to the MainViewModel's properties yet! How can this be? I thought AreSame checks whether two references point to the same instance.
public class MainViewModel
{
private readonly FacilityDataEntity facilityDataEntity;
private readonly ShopOrderDataEntity shopOrderDataEntity;
public MainViewModel(FacilityDataEntity facilityDataEntity)
{
this.facilityDataEntity = facilityDataEntity;
}
public MainViewModel(FacilityDataEntity facilityDataEntity, ShopOrderDataEntity shopOrderDataEntity)
{
this.facilityDataEntity = facilityDataEntity;
this.shopOrderDataEntity = shopOrderDataEntity;
}
public ShopOrderDataEntity ShopOrderDataEntity
{
get { return shopOrderDataEntity; }
}
public FacilityDataEntity FacilityDataEntity
{
get { return facilityDataEntity; }
}
public int ShopOrder { get; set; }
public decimal RequiredQuantity { get; set; }
public string ItemCode { get; set; }
public string ItemDescription { get; set; }
public string FacilityValue { get; set; }
public string FacilityLabel { get; set; }
public static IEnumerable<MainViewModel> TranslateDataEntityList(IEnumerable<FacilityDataEntity> facilityDataEntityList)
{
foreach (FacilityDataEntity facilityDataEntity in facilityDataEntityList)
{
yield return new MainViewModel(facilityDataEntity);
}
}
public static IEnumerable<MainViewModel> TranslateDataEntityList(FacilityDataEntity facilityDataEntity, IEnumerable<ShopOrderDataEntity> shopOrderDataEntityList)
{
foreach (ShopOrderDataEntity shopOrderDataEntity in shopOrderDataEntityList)
{
yield return new MainViewModel(facilityDataEntity, shopOrderDataEntity);
}
}
}

Underneath it all, these tests are just using Object.ReferenceEquals:
true if objA is the same instance as objB or if both are null; otherwise, false.

I guess this is happening because they are both null.

in this case, I'd say its comparing null with null, which are the same.

how to integrate two classes

i am working on a small app that mange flights, i have a class that build a flight details and class that build the passenger, now, i want to load the passengers onto a flight, how should i do it? do i need to build a higer class that inherit from this two class and make a list of that type of class(i dont think that wise oop ).or should i add a ticket prop in the passenger class that have the flight number, here is my code.
public class Passenger
{
public Passenger(string name, int passportNumber)
{
this.PassengerName = name;
this.PassportNumber = passportNumber;
}
private string _passengerName;
public string PassengerName
{
get { return _passengerName; }
set { _passengerName = value; }
}
private int _passportNumber;
public int PassportNumber
{
get { return _passportNumber; }
set { _passportNumber = value; }
}
}
public class FlightDetails
{
public FlightDetails(int flightNumber, string flightDestination, string planmodel)
{
this.FlightNumber = flightNumber;
this.FlightDestination = flightDestination;
this.PlanModel = planmodel;
}
private int _flightNumber;
public int FlightNumber
{
get { return _flightNumber; }
set { _flightNumber = value; }
}
private string _flightDestination;
public string FlightDestination
{
get { return _flightDestination; }
set { _flightDestination = value; }
}
private string _planeModel;
public string PlanModel
{
get { return _planeModel; }
set { _planeModel = value; }
}
}
static void Main(string[] args)
{
List<FlightDetails> flightList = new List<FlightDetails>();
FlightDetails a = new FlightDetails(12,"france","jumbo");///create a flight
flightList.Add(a);/// load up the flight
}

First, you can't create a class that inherits from both other classes because multiply inheritance is not allowed in C#.
You can use aggregation, something like this:
public class FlightDetails
{
// ...
}
public class Passenger
{
// ...
}
public class Flight
{
public FlightDetails { get; private set; }
public List<Passenger> Passengers { get; private set; }
public Flight(FlightDetails details)
{
FlightDetails = details;
Passengers = new List<Passenger>();
}
public AddPassenger(Passenger p)
{
// check for ticket and so on..
Passengers.Add(p);
}
}
You can read more about aggregation here: http://en.wikipedia.org/wiki/Object_composition#Aggregation
Note that in this example for simplicity i used List but actually you need to limit access to this array (because otherwise i can do something like this: Flight.Passengers.Add(p) instead of Flight.AddPassenger(p)) so good idea will be use ReadOnlyCollection as public interface to this list.

Here's a sample code that might work. A flight has one or more passengers, thus has a List of type Passenger. In real-life, a passenger can book multiple flights. If you want the reality, you'll have to change your model but for this situation it'll work:
public class Passenger
{
public Passenger(string name, int passportNumber)
{
PassengerName = name;
PassportNumber = passportNumber
}
public string PassengerName { get; set; }
public int PassportNumber { get; set; }
}
public class FlightDetails
{
public FlightDetails(int flightNumber, string flightDestination, string planmodel)
{
FlightNumber = flightNumber;
FlightDestination = flightDestination;
PlanModel = planmodel;
Passengers = new List<Passengers>();
}
public int FlightNumber { get; set; }
public string FlightDestination { get; set; }
public string PlanModel { get; set; }
public List<Passenger> Passengers { get; private set; }
public void AddPassenger(string name, int number)
{
int max = 2;
int passengersNumber = Passengers.Count;
if (passengersNumber < max)
{
Passengers.Add(new Passenger(name, number);
}
}
public static void Main(string[] args)
{
var flightList = new List<FlightDetails>();
var passengersList = new List<Passenger>();
//Add passenger-objects to passengers-list
var flightOne = new FlightDetails(12, "France", "Jumbo");
flightOne.Passengers = passengersList;
flightList.Add(a);
}
Here's a better solution to limit the passengers:
public class FlightDetails
{
public FlightDetails(int flightNumber, string flightDestination, string planmodel)
: this(flightNumber, flightDestination, planmodel, new List<Passenger>())
{
}
public FlightDetails(int flightNumber, string flightDestination, string planmodel, List<Passenger> passengers)
{
FlightNumber = flightNumber;
FlightDestination = flightDestination;
PlanModel = planmodel;
if(passengers.Count > 2)
//throw exception or error
else
_passengers = passengers;
}
private List<Passenger> _passengers = new List<Passenger>();
public int FlightNumber { get; set; }
public string FlightDestination { get; set; }
public string PlanModel { get; set; }
public IEnumerable<Passenger> Passengers { get { return _passengers; } }
public void AddPassenger(string name, int number)
{
int max = 2;
int passengersNumber = _passengers.Count;
if (passengersNumber < max)
{
_passengers.Add(new Passenger(name, number);
}
}
}
Note: this code is written without compiling. But the idea is correct normally. :)

In logical way, relation between FlightDetail to Passenger is OneToMany. One FlightDetail can have multiple Passenger which is can be written as below. FlightDetail and Passenger should be have any common inheritance hierarchy because they are don't have any common attribute or behaviour.
public class FlightDetails
{
private List<Passenger> passengerList;
public void addPassenger(Passenger p){
if(passengerList == null){
passengerList = new ArrayList<Passenger>();
}
passengerList.add(p);
}
public List<Passenger> getPassengerList(){
return passengerList;
}
//... your other detail
}

You should add a FlightDetails property to your Passenger class. That's easier than making a List with PassportNumber as index. But, it's easier to iterate FlightDetails using List, than accessing it through Passenger.

It actually depends on how you want to access and store the relations.
It might be a good idea to read about the composite pattern which actually has a nice solution for travelling between parent-child relations, even though the pattern has another purpose.