I have classes that has multiple properties which have well-defined name and function but have the same implementation. For example:
class Stats
{
private int attack;
public int Attack
{
get =>
HasBuff ? attack + 1 : attack;
set
{
if (value < 1 || value > 10)
throw new ArgumentOutOfRangeException("Invalid value");
attack = value;
}
}
public int Defense {...}
public int Speed {...}
}
Where Defense and Speed are to be implemented just like Attack . How can I generalize this structure to avoid redundancy and make changes easier?
Make another class to generalize stats:
public class Stat
{
public bool HasBuff { get; set; }
private int _stat;
public int Score
{
get => HasBuff ? _stat + 1 : _stat;
set => _stat = value;
}
}
Then just use that for each of your skills:
public class CombatStats
{
public Stat Attack { get; } = new Stat();
public Stat Defense { get; } = new Stat();
public Stat Speed { get; } = new Stat();
}
Calling code would look like this:
var ninja = new Ninja();
ninja.skills = new CombatStats();
var attackStrength = ninja.skills.Attack.Score;
As further improvement, implicit operators can be used to avoid object creation and call to Score:
public class Stat
{
...
public static implicit operator int(Stat stat)
{
return stat.Score;
}
public static implicit operator Stat(int value)
{
return new Stat()
{
Score = value
};
}
}
This makes the change transparent to client code written w.r.t. to the example in the question:
ninja.skills = new CombatStats(){
Attack = 5,
Defense = 2
}
int attack = ninja.skills.Attack;
One approach to consider:
class Stats
{
// other existing code here
private int defense;
public int Defense
{
get
{
return GetValue(defense);
}
set
{
SetValue(value, ref defense);
}
}
private int GetValue(int value)
{
return HasBuff ? value + 1 : value;
}
private void SetValue(int value, ref int target)
{
if (value < 1 || value > 10)
throw new ArgumentOutOfRangeException("Invalid value");
target = value;
}
}
Attack etc will now be basically the same as Defence but passing in attack rather than defense to GetValue and SetValue.
I would go with composition
Stat:
public class Stats
{
private readonly StatProperty _defense;
private readonly StatProperty _attack;
private readonly StatProperty _speed;
public Stats()
{
_defense = new StatProperty(this);
_attack = new StatProperty(this);
_speed = new StatProperty(this);
}
public int Defense
{
get => _defense.Value;
set => _defense.Value = value;
}
public int Attack
{
get => _attack.Value;
set => _attack.Value = value;
}
public int Speed
{
get => _speed.Value;
set => _speed.Value = value;
}
public bool HasBuff { get; set; }
}
StatProperty:
public class StatProperty
{
public Stats Stats { get; }
public StatProperty(Stats stats)
{
Stats = stats;
}
private int _value = 1;
public int Value
{
get => Stats.HasBuff ? _value + 1 : _value;
set
{
if (value < 1 || value > 10)
throw new ArgumentOutOfRangeException("Invalid value");
_value = value;
}
}
}
I would need more details to know if it is the best option.
you also could make StatProperty as internal if don't want to show it outside of your library or nested private class if you want to use this just on the class Stats
Related
I was expected that constructor can go into the setter condition, I have done the following attempts.
static void Main(string[] args)
{
Iitem car = new Car(7000);
Console.WriteLine($"cost={car.cost}");//expect output "too expensive",but actually show 7000
car.cost = 7000;
Console.ReadLine();
}
public interface Iitem
{
int cost { get; set; }
string status {get;set; }
}
class Car:Iitem
{
private int mycost;
public int cost
{
get { return mycost; }
set
{
if (value > 5000)
{
mycost = 0;
Console.WriteLine("too expensive");
}
else
{
mycost = value;
}
}
}
public string status { get; set; }
public Car(int cost)
{
this.mycost = cost;
}
}
If I discard car.cost=7000 from Main() function, then I can't get the output of too expensive.
you are not getting the desired result because you are setting the value directly into the variable "mycost" in the constructor. Replace it with this.cost = cost;
I created a trading system with an adaptive moving average on the average true range but the program reports this error to me
the modifier public is not valid for this item
at line 21 of the code
public int avgTrueRange.value1 { get; set; }
I tried to change public but it always reports this error.
this is the code :
public class MediaMobileAdattiva : SignalObject
{
public MediaMobileAdattiva(object _ctx): base(_ctx)
{
Range = 14;
FirstLength = 10;
AvgTrueRange.value1 = 1;
}
private IOrderMarket buy_order;
public int Range { get; set; }
public double FirstLength { get; set; }
public int AvgTrueRange.value1 { get; set; }
private double FirstAverage()
{
if (AverageTrueRange < AvgTrueRange.value1)
return FirstLength;
}
protected override void Create()
{
// create variable objects, function objects, order objects
buy_order = OrderCreator.MarketNextBar(new SOrderParameters(Contracts.Default, EOrderAction.Buy));
}
protected override void StartCalc()
{
// assign inputs
}
protected override void CalcBar()
{
// strategy logic
if (Bars.CurrentBar > 1)
{
switch (FirstAverage)
{
case FirstLength:
return 1;
}
}
if (Bars.CurrentBar > 1 && Bars.Close.CrossesOver(FirstAverage, ExecInfo.MaxBarsBack)
{
switch (FirstLength)
{
case 1:
buy_order.Send(Bars.Close[0]);
}
}
}
}
What you need is to make a struct for AvgTrueRange:
public struct Range
{
public int value1 {get; set;}
}
and change:
public int AvgTrueRange.value1 { get; set; }
to
public Range AvgTrueRange { get; set; }
Your code still won't compile btw but I don't really understand what you are trying to do in this line:
if (AverageTrueRange < AvgTrueRange.value1)
Also, change:
switch (FirstAverage)
{
case FirstLength:
return 1;
}
to
var avg = FirstAverage();
int? result = avg switch
{
var avg when avg == FirstLength => 1,
_ => null
};
if (result.HasValue) return result.Value;
as cases can only be constant values.
As shown in the first class displayed, I need to cast Activité to Réunion (Réunion extends Activité) but the compiler tells me that I can't. Why? I'll put a scheme so you can better understand my classes structure and also all my other classes. Thank you.
class Employé<T>
{
private string nom;
private Local bureau;
private LinkedList<Activité<T>> activités;
public Employé(string nom, Local bureau)
{
this.nom = nom;
this.bureau = bureau;
}
public void AjouteActivité(params Activité<T>[] activités)
{
foreach(Activité<T> activité in activités)
{
if (activité as Réunion != null)
// here's the problem !!! ((Réunion)activité).EmployéConvoqués = activité;
}
}
}
Here's the scheme of my classes structure:
And here are the other classes:
abstract class Activité<T>
{
private string label;
private DateTime début, fin;
private T lieu;
private readonly int id;
private static int CPT = 0;
public Activité(string label, DateTime début, DateTime fin, T lieu)
{
this.label = label;
this.début = début;
this.fin = fin;
this.lieu = lieu;
this.id = ++CPT;
}
public override string ToString()
{
return $"{id} : {label}(de {début} à {fin}) - {DescriptionLieu()}";
}
public double Duree()
{
return fin.Subtract(début).TotalMinutes;
}
public int Id
{
//tester get; seulement
get
{
return id;
}
}
public T Lieu
{
get
{
return lieu;
}
}
public abstract string DescriptionLieu();
}
class ActivitéExtérieure : Activité<string>
{
public ActivitéExtérieure(string label, DateTime début, DateTime fin, string lieu) : base(label,début,fin,lieu) { }
public override string DescriptionLieu()
{
return Lieu;
}
}
class ActivitéInterne : Activité<Local>
{
public ActivitéInterne(string label, DateTime début, DateTime fin, Local lieu) : base(label,début,fin,lieu)
{
lieu.AjouteActivité(this);
}
public override string DescriptionLieu()
{
return $"local :: {Lieu.NumComplet}";
}
}
class Employé<T>
{
private string nom;
private Local bureau;
private LinkedList<Activité<T>> activités;
public Employé(string nom, Local bureau)
{
this.nom = nom;
this.bureau = bureau;
}
public void AjouteActivité(params Activité<T>[] activités)
{
foreach(Activité<T> activité in activités)
{
if (activité as Réunion != null)
((Réunion)activité).EmployéConvoqués = activité;
}
}
}
class Local
{
private int etage;
private int numero;
private bool possedeWifi;
private Dictionary<int, ActivitéInterne> historiquesActivités;
public int Numero
{
get
{
return numero;
}
set
{
if (value < 0 || value > 99)
throw new IndexOutOfRangeException();
else
numero = value;
}
}
public int NumComplet
{
get
{
return etage * 100 + numero;
}
}
public bool PossedeWifi
{
get
{
return possedeWifi;
}
}
public Local(int etage, bool possedeWifi, int numero)
{
this.etage = etage;
this.possedeWifi = possedeWifi;
Numero = numero;
}
public Local(int etage, int numero) : this(etage, true, numero) { }
public Local(int local, bool possedeWifi) : this(local / 100, possedeWifi, local % 100) { }
public void AjouteActivité(ActivitéInterne a)
{
historiquesActivités.Add(a.Id, a);
}
}
class Réunion : ActivitéInterne
{
private HashSet<Employé<Local>> employésConvoqués;
public Réunion(string label, DateTime début, DateTime fin, Local lieu) : base(label, début, fin, lieu) { }
public Employé<Local> EmployéConvoqués
{
set
{
employésConvoqués.Add(value);
}
}
}
The error message says that "cast is redundant". This is because you have already tested for "activité as Réunion != null". The compiler figures out that in the 'if' clause this condition is already true, therefore the cast is not meaningful. On the other hand you cannot access activité.EmployéConvoqués because the static type of activité is not Réunion.
All you have to do is introduce a new variable when testing the type. Like this:
if (activité is Réunion réunion) {
réunion.EmployéConvoqués = activité;
}
However if you try this you will see that the assignment cannot be done because you are trying to assign an activity to an Employé<Local>. These are not compatible types. Perhaps you meant something like
foreach (Activité<T> activité in activités) {
if (activité is Réunion réunion && this is Employé<Local> employéLocal) {
réunion.EmployéConvoqués = employéLocal;
}
}
Comment: in the definition of Réunion you are adding to HashSet<Employé<Local>> employésConvoqués when setting the property Employé<Local> EmployéConvoqués. From a style point of view this is strange because people generally expect a property of type Employé<Local> will represent a single Employé<Local> rather than a collection of Employé<Local>. I would suggest that you remove the setter and instead define
public void Ajoute( Employé<Local> employéConvoqué) {
this.employésConvoqués.Add(employéConvoqué);
}
This is the first class:
public class TextBoxInt : TextBox
{
public int min;
public int max;
public Value<int> value;
public virtual void Update(object sender, EventArgs e)
{
int newValue;
if (int.TryParse(Text, out newValue))
{
if (newValue < min || newValue > max)
{
//do thing A
}
value.Set(newValue);
Text = value.Get().ToString();
}
else
{
Text = value.Get().ToString();
Focus();
}
}
public TextBoxInt(Value<int> value, int min, int max)
{
this.value = value;
this.min = min;
this.max = max;
Text = value.Get().ToString();
LostFocus += new EventHandler(update);
}
}
This is the second class:
public class TextBoxFloat : TextBox
{
public float min;
public float max;
public Value<float> value;
public virtual void Update(object sender, EventArgs e)
{
float newValue;
if (float.TryParse(Text, out newValue))
{
if (newValue < min || newValue > max)
{
//do thing A
}
value.Set(newValue);
Text = value.Get().ToString();
}
else
{
Text = value.Get().ToString();
Focus();
}
}
public TextBoxFloat(Value<float> value, float min, float max)
{
this.value = value;
this.min = min;
this.max = max;
Text = value.Get().ToString();
LostFocus += new EventHandler(update);
}
}
Also, this is the Value class :
public class Value<T>
{
private T value;
private List<IValueListener<T>> listeners = new List<IValueListener<T>>();
public Value(T value)
{
this.value = value;
}
public T Get()
{
return value;
}
public void Set(T value)
{
this.value = value;
foreach (IValueListener<T> listener in listeners)
{
listener.ValueUpdated(this);
}
}
public void AddListener(IValueListener<T> listener)
{
listeners.Add(listener);
}
public void RemoveListener(IValueListener<T> listener)
{
listeners.Remove(listener);
}
}
As you can see, the first two classes are basically the same class. The only difference is the type. First one is int, the other one float. It seems that I would make for nicer code if I could combine those two into a single class.
I can set min and max to be floats and just cast them to int when needed if it's an int class. I'd just make sure I pass "whole" floats when the type is int.
Is there any way I can do it without duplicating Update() method (If int do codeForInt, else if float do sameCodeButForFloat)?
Also, even if I do duplicate the code, I run into a problem with value.Set(newValue); - in one case newValue would be int, in other it would be float, and I can't cast either to T.
Also, is there a way to limit the generic type? To specify it can only be int or a float?
Should I just leave them as two classes, or is there a way to unify them?
Instead of making separate classes, you could make a generic class.
public class BoundedTextBox<T> : TextBox where T : IComparable<T> ...
Declaring that T implements IComparable<T> will allow you to check if T is in bounds during your set operation.
if (newValue.CompareTo(min) <= 0 || newValue.CompareTo(max) >= 0)
{
// do thing A
}
What about having an abstract TextBox<T> class inheriting from the TextBox class, where TextBox<T> has a new abstract string GetValue() method? You'll have TextBoxFloat class implementing GetValue() which will do the float specific logic and similarly will the TextBoxInt class. Your TextBox<T> would be something like
public abstract class TextBox<T> : TextBox
{
public T min;
public T max;
public Value<T> value;
public virtual void Update(object sender, EventArgs e)
{
Text = GetValue();
Focus();
}
public TextBoxFloat(Value<T> value, T min, T max)
{
this.value = value;
this.min = min;
this.max = max;
Text = value.Get().ToString();
LostFocus += new EventHandler(update);
}
public abstract string GetValue();
}
As #flkes stated, a generic class is the way to go on this one. You could try something along these lines: (you can find a fine example Here)
public abstract class TextBoxBase
{
public abstract object GetMin();
public abstract object GetMax();
public abstract object GetValue();
}
public abstract class TextBox<T> : TextBoxBase
{
public T min { get; set; }
public T max { get; set; }
public T value { get; set; }
public virtual void SetTextBox(T mn, T mx, T val)
{
min = mn;
max = mx;
value = val;
}
public override object GetMin() { return min; }
public override object GetMax() { return max; }
public override object GetValue() { return value; }
}
public class TextBoxInt : TextBox<int>
{
public override void SetTextBox(int mn, int mx, int val)
{
min = mn;
max = mx;
value = val;
}
}
public class TextBoxFloat : TextBox<float>
{
public override void SetTextBox(float mn, float mx, float val)
{
min = mn;
max = mx;
value = val;
}
}
I am new to C# and was asked to create two class definitions (customer and order) using partial code and with the suggested class names, methods, contructors and following an example. I am not sure why I am getting so many errors when I build/debug?
After this is finished, I need to create another program that builds onto this one. Our instructor also asked us not to use validation...
Some of my most common errors are:
expected: ; (in a place in my code where I believe there should not be a semi-colon and
Error "Expected class, delegate, enum, interface, or struct.
Here is my code:
public class clsOrder
{
//declare class variables
protected string cstrDescription;
protected int cintQuantity;
protected decimal cdecPrice;
protected decimal cdecExtendedPrice;
//shared variables
static decimal cdecTotalPrice;
static int cintTotalCount;
//declare constructors
public clsOrder();
}
public clsOrde r(string strDescription,
int intQuantity, decimal decPrice)
}
//declare property methods
{
this.Description = string strDescription;
this.Quantity = int intQuantity;
this.Price = decimal decPrice;
//declare read-only properties
public decimal ExtendedPrice
}
public string Description
{
get
{
return strDescription;
}
set
{
strDescription = value;
}
}
public int Quantity
{
get
{
return intQuantity;
}
set
{
intQuantity = value;
}
}
public decimal Price
{
get
{
return decPrice;
}
set
{
decPrice = value;
}
}
get
{
return cdecExtendedPrice;
}
}
//declare Shared (static) ReadOnly Properites
public static decimal TotalPrice
{
get
{
return cdecTotalPrice;
}
}
public static int TotalCount
{
get
{
return cintTotalCount;
}
}
//declare supporting methods
public void calcExtendedPrice()
{
cdecExtendedPrice = cintQuantity * cdecPrice;
}
public void accumulateTotals()
{
cdecTotalPrice += cdecExtendedPrice;
cintTotalCount += 1;
}
public static void resetTotals()
{
cdecTotalPrice = 0;
cintTotalCount = 0;
}
}//end of Class
}//end of namespace
And
public class clsCustomer
{
//declare class variables
private string cstrName;
private string cstrStreet;
private string cstrCity;
private string cstrState;
private string cstrZip;
//declare constructors
public class clsCustomer()
}
public clsCustomer(string strName,
string strStreet, string strCity,
string strState, string strZip)
}
//declare property methods
{
this.Name = cstrName;
this.Street = cstrStreet;
this.City = cstrCity;
this.State = cstrState;
this.Zip = cstrZip;
}
public string Name
{
get
{
return cstrName;
}
set
{
cstrName = value;
}
}
public string Street
{
get
{
return cstrStreet;
}
set
{
cstrStreet = value;
}
}
public string City
{
get
{
return cstrCity;
}
set
{
cstrCity = value;
}
}
public string State
{
get
{
return cstrState;
}
set
{
cstrState = value;
}
}
public string Zip
{
get
{
return cstrZip;
}
set
{
cstringZip = value;
}
}
Any help would be very much appreciated, thank you.