Develop Reference

c# (and maybe unity) - why is singleton not instantiated?

I listened to the youtube unity tutorial https://www.youtube.com/watch?v=gCqOnchV4V0&t=2491s, in which it talked about defining singleton (at 59:29) like this:
public class GameManager : MonoBehaviour
{
public static GameManager Instance { get; private set; }
int scoreCount=0;
//...
}
//when using the instance:
class Player : MonoBehaviour
{
//...
GameManager.Instance.scoreCount++;
//...
}
This method works in the first small unity game I made. However, when I use it the second time I failed to create an instance. Thus I decided to test it again.
using System;
namespace ConsoleApp1
{
class classiii
{
static void Main(string[] args)
{
string input = Console.ReadLine();
int result = Int32.Parse(input);
Console.WriteLine(Program.Instance.A(result));
Console.ReadLine();
}
}
class Program
{
public static Program Instance { get; private set; }
int firstNum = 5;
public int A(int tmp)
{
return firstNum + tmp;
}
}
}
So why is this not working? Why is it working in the first unity project?

Try to display a int through a static field, but return a weird value (C#)

I'm trying to cut down on how much duplication I have on my code, so I decided to make one of my classes a static class since I decided that its data should really be shared with everyone. Here's the static method below:
// A static class, that holds all object's coordinates, and methods to return & update their values.
internal static class Coordinate
{
private static int[,] PlayerCoordinate { get; set; }
public static int[,] GateCoordinate { get; }
public static int[,] FountainCoordinate { get; }
static Coordinate() // FIRST VALUE IS X (column), SECOND VALUE IS Y (row).
{
PlayerCoordinate = new int[,] { { 0, 0 } };
GateCoordinate = PlayerCoordinate; // Just starts off in the same place as player.
FountainCoordinate = new int[,] { { 2, 0 } };
}
// A static method, that sends the data of all object coordinates, deconstructed into seperate ints.
public static int PlayerColumn() { return PlayerCoordinate[0, 0]; }
public static int PlayerRow() { return PlayerCoordinate[0, 1]; }
public static int GateColumn() { return GateCoordinate[0, 0]; }
public static int GateRow() { return GateCoordinate[0, 1]; }
public static int FountainColumn() { return FountainCoordinate[0, 0]; }
public static int FountainRow() { return FountainCoordinate[0, 1]; }
// Updates the coordinates of the player.
public static void UpdatePlayerCoordinate(int column, int row) { PlayerCoordinate = new int[,] { { column, row } }; }
}
The main issue comes in from my GameManager class. On the console, the beginning section should print out "You are the room at (Column=0, Row=0), but it prints this instead:
Here is the code for my GameManager class:
internal class GameManager
{
private bool IsGameOver;
private Player Player;
private Updater Updater;
// Don't need to call Fountain or Coordinate since they're static
public GameManager()
{
IsGameOver = false;
Player = new();
Updater = new();
}
public void RunGame()
{
while (!IsGameOver)
{
Console.WriteLine("----------------------------------------------------------");
Updater.DisplayPlayerPosition(); // This is the main line that I'm having issues with as of right now. All other functions past this are another problem.
Updater.DisplayPlayerSenses();
string playerInput = Player.GetInput();
Updater.MovePlayer(playerInput);
IsGameOver = Updater.CheckForWin();
}
}
}
And just to make sure, here is the code from my updater class, with the specific method that I'm having issues with:
internal class Updater
{
// No fields
// Default constructor
// Gets the text to show the player his current position.
public void DisplayPlayerPosition() // This is the method that I'm having issues with.
{
Console.WriteLine($"You are in the room at (Column={Coordinate.PlayerColumn}, Row={Coordinate.PlayerRow})");
}
...
I'm fairly new to the static keyword so I believe that I may be missing smth. I personally believe that it's because the class itself hasn't been initialized (like I haven't called the constructor for the Coordinate class, and apparently you can't call a static constructor anyways), but that's just me. If I could get any help, I'd greatly appreciate it!

PlayerColumn() and PlayerRow() are methods, but you are accesing them in the WriteLine statement as if they are properties.
Update your WriteLine to:
Console.WriteLine($"You are in the room at (Column={Coordinate.PlayerColumn()}, Row={Coordinate.PlayerRow()})");

How to use an enum to choose between multiple script option using c#

Here is the code I am using:
public enum TargetingOptions
{
NoTarget,
AllCreatures,
EnemyCreatures,
YourCreatures,
AllCharacters,
EnemyCharacters,
YourCharacters
}
public enum Faction
{
Fog,
Imperial,
Monster,
Pirate
}
public class CardAsset : ScriptableObject
{
public CharacterAsset characterAsset;
[TextArea(2, 3)]
public string Description;
public Sprite CardImage;
public int ManaCost;
[Header("Faction")]
public Faction faction;
[Header("Creature Info")]
public int MaxHealth;
public int Attack;
public int AttacksForOneTurn = 1;
public bool Charge;
public string CreatureScriptName;
public int specialCreatureAmount;
[Header("SpellInfo")]
public string SpellScriptName;
public int specialSpellAmount;
public TargetingOptions Targets;
}
what I am trying to do is create a different "hand" of cards depending on faction. to do this I have created a separate "hand" script for each of the factions, but I want to create a "handmultiple" script that will choose which "hand faction" script to head to.
So if in unity "pirate" is chosen, then all that will appear would be the associated scripts (ignoring fog, imperial and pirate scripts)
Does that make sense?
thank you!
enter code here using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using DG.Tweening;
public class HandVisualImperial : MonoBehaviour
{
public AreaPosition owner;
public bool TakeCardsOpenly = true;
public SameDistanceChildren slots;
[Header("Transform References")]
public Transform DrawPreviewSpot;
public Transform DeckTransform;
public Transform OtherCardDrawSourceTransform;
public Transform PlayPreviewSpot;
private List<GameObject> CardsInHand = new List<GameObject>();
public void AddCard(GameObject card)
{
CardsInHand.Insert(0, card);
card.transform.SetParent(slots.transform);
PlaceCardsOnNewSlots();
UpdatePlacementOfSlots();
}
public void RemoveCard(GameObject card)
{
CardsInHand.Remove(card);
PlaceCardsOnNewSlots();
UpdatePlacementOfSlots();
}

So I think I have it figured out:
Have a whole bunch more work to do before testing it unfortunately.. but I believe I have it done now... Thank you all for the help!!!
public class HandVisualMultiple : MonoBehaviour
{
Faction factiontype;
public HandVisualFog fog;
public HandVisualImperial imperial;
public HandVisualMonster monster;
public HandVisualPirate pirate;
void Start()
{
fog = GetComponent<HandVisualFog>();
imperial = GetComponent<HandVisualImperial>();
monster = GetComponent<HandVisualMonster>();
pirate = GetComponent<HandVisualPirate>();
if (factiontype == Faction.Fog)
{
fog.enabled = true;
imperial.enabled = false;
monster.enabled = false;
pirate.enabled = false;
}
else if (factiontype == Faction.Imperial)
{
fog.enabled = false;
imperial.enabled = true;
monster.enabled = false;
pirate.enabled = false;
}
else if (factiontype == Faction.Monster)
{
fog.enabled = false;
imperial.enabled = false;
monster.enabled = true;
pirate.enabled = false;
}
else if (factiontype == Faction.Pirate)
{
fog.enabled = false;
imperial.enabled = false;
monster.enabled = false;
pirate.enabled = true;
}
}
}

It's not the answer for your question, but an experienced game developer advice.
Try to use Polimorfism. A single main class. "class Creature" and then a lot of child classes class ImperialCreature:Creature, class PirateCreature:Creature and then set the parameters to each of them.
And later you can set another sub classes. for instance: class JackSparrow:PirateCreature ... and on...

The enum is similar to an array, so if you do (int)Faction.Fog it will return 0 since it's the first item. You could have an array or list with your scripts in the same order as your enum and call them by casting the enum to an int

C# Access Struct using String

I am a bit stuck with my game. I have a class called Upgradebuttons. From this class I want to access some variables stored in a struct from another class. I can easily access the variables by typing classname.structname.preferedvar but the structname depends on which upgrade as been clicked. So I want to call the struct using a string. I have tried:
MethodInfo method = typeof(Classname).GetMethod(structname);
But this only works if it is a void and not a struct. What do I need to do in order to get this working?
public class UpgradeButtons : MonoBehaviour {
public void somefunction{
// here i want to have access
}
}
This is an example of the class I want to have access to:
public class Upgrades: MonoBehaviour {
public struct Upgrade1{
public const int Cost = 10;
public const float Value = 0.1f;
public static string Naam = "Autoclicker";
}
}

While this is possible, it sounds like poorly thought out design. Perhaps you could use one common struct Upgrade and use the Name property to find it at runtime?
Example:
public struct Upgrade
{
public string Name;
public int Cost;
public float Value;
public Upgrade(string name, int cost, float value)
{
this.Name = name;
this.Cost = cost;
this.Value = value;
}
}
public class UpgradeButtons : MonoBehavior
{
List<Upgrade> Upgrades = new List<Upgrade>();
public void CreateButtons()
{
Upgrades.Add(new Upgrade("Autoclicker", 10, 0.1f));
//etc...
}
public void somefunction()
{
Upgrade autoclickUpgrade = Upgrades.Where(p => p.Name == "Autoclicker").FirstOrDefault();
if(autoclickUpgrade == null)
throw new Exception("Could not find Autoclicker upgrade.");
//do something with autoclickUpgrade
}
}

just remove static from string Naam:
public class Upgrades: MonoBehaviour {
public struct Upgrade1{
public const int Cost = 10;
public const float Value = 0.1f;
public string Naam = "Autoclicker";
}
}
When an object ( class, variable, method) is defined as static it can not be referenced through an instance.

If I understand your question, you are on the right track, probably. Since the struct (type) that your add-on depends on may or may not exist, Reflection is the best way to go here.
Try Assembly.GetType(), or a related method, to attempt to load the type, check its existence, and iterate its members.
http://msdn.microsoft.com/en-us/library/y0cd10tb(v=vs.110).aspx

Creating a generic list of objects in C#

By way of an intro, I'm creating a basic Quadtree engine for personal learning purposes. I'm wanting this engine to have the capability of working with many different types of shapes (at the moment I'm going with circles and squares) that will all move around in a window and perform some sort of action when collision occurs.
Here are my shape objects as I have them so far:
public class QShape {
public int x { get; set; }
public int y { get; set; }
public string colour { get; set; }
}
public class QCircle : QShape {
public int radius;
public QCircle(int theRadius, int theX, int theY, string theColour) {
this.radius = theRadius;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
}
public class QSquare : QShape {
public int sideLength;
public QSquare(int theSideLength, int theX, int theY, string theColour) {
this.sideLength = theSideLength;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
}
Now my question is, how do I create a generic list (List<T> QObjectList = new List<T>();) in C# so I can have one list containing all these various shapes that may have different properties (e.g., QCircle has the "radius" property while QSquare has the "sideLength" property)? An example of implementation would be helpful as well.
I just know that there is a stupidly obvious answer to this question but I'd appreciate any help anyway. I'm trying to get back into C#; it has obviously been a while...

You need to use downcasting
Store the objects in a list with the base class
List<QShape> shapes = new List<QShape>
You can then upcast the object safely if you know what it is e.g.
if(shapes[0] is QSquare)
{
QSquare square = (QSquare)shapes[0]
}
You can also implicitly downcast objects
QSquare square = new Square(5,0,0,"Blue");
QShape shape = square
For more information read the Upcasting and Downcasting sections here

You should implement an Interface. For example
public interface IHasLength
{
int Length;
}
Then in the implementation you can do
public class QSquare : QShape, IHasLength {
public int sideLength;
public QSquare(int theSideLength, int theX, int theY, string theColour) {
this.sideLength = theSideLength;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
public int Length { get { return sideLength; } }
}
public class QCircle : QShape, IHasLength {
public int radius;
public QSquare(int theSideLength, int theX, int theY, string theColour) {
this.sideLength = theSideLength;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
public int Length { get { return radius; } }
}
FInally, in your list:
List<IHasLength> shapesWithSomeLength = new List<IHasLength>();
Now your list can hold ANYTHING that implements IHasLength whether it's a QCircle, QShape, or even a QDuck if you want as long as it implements IHasLength.

Is this what you want?
public class QShape
{
protected QShape() { }
public int x { get; set; }
public int y { get; set; }
public string colour { get; set; }
}
public class QCircle : QShape
{
public int radius;
public QCircle(int theRadius, int theX, int theY, string theColour)
{
this.radius = theRadius;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
}
public class QSquare : QShape
{
public int sideLength;
public QSquare(int theSideLength, int theX, int theY, string theColour)
{
this.sideLength = theSideLength;
this.x = theX;
this.y = theY;
this.colour = theColour;
}
}
class Program
{
static void Main(string[] args)
{
List<QShape> list = new List<QShape>();
list.Add(new QCircle(100, 50, 50, "Red"));
list.Add(new QCircle(100, 400, 400, "Red"));
list.Add(new QSquare(50, 300, 100, "Blue"));
foreach (var item in list.OfType<QCircle>())
{
item.radius += 10;
}
foreach (var item in list.OfType<QSquare>())
{
item.sideLength += 10;
}
}
}

You could store them in a List<QShape> but this would mean that you could not access type-specific properties.
Generally, you might approach this by providing a common interface in your base class, and overriding behaviour in subclasses. In this way, a common interface can hide a diverse bunch of behaviours. For instance a Grow method could hide the complexities of growing items of different shape and could be called without explicit knowlege of the shape upon which it is operating.
public abstract class QShape {
public abstract void Grow(int amt);
}
public class QSquare : QShape {
private int sideLength;
public override void Grow(int amt)
{
sideLength+=amt;
}
}
public class QCircle : QShape {
private int radius;
public override void Grow(int amt)
{
radius+=amt;
}
}

I feel like i'm missing something but...
List<QCircle> circleObjects = new List<QCircle>();
and
List<QSquare> squareObjects = new List<QSquare>();
will work perfectly well.
EDIT:
Ah, I didn't understand what was being asked.
Yes, as your QCircle and QSquare classes inherit from QShape, you can just do.
List<QShape> shapes= new List<QShape>();
It's worth noting that if you want to access the radius property of all the QCircle's in that list, then you are going to have to filter the list based on type.

You can use Ian Mercer's comment List<QShape>
And here's how you would fill it:
List<QShape> shapes = new List<QShape>();
QCircle circle = new QCircle();
shapes.Add(circle);
To unbox it:
QCircle circle = (QCircle) shapes[0];
If you need to call a method off the base class, no need to unbox, just use it.

Storing
You're already on the right track with your class definitions. What you have to do is make a List of the superclass (in this case, QShape), which will be able to hold all of your shapes.
Here's an example of how you would make it:
List<QShape> objects = new List<QShape>();
objects.add(new QCircle(...));
objects.add(new QSquare(...));
Accessing
The problem here is differentiating what is what once everything is in the list. That's done with the getType() and typeof() methods of C#. (Jon Skeet has an excellent answer about how to do this). Basically, it looks like this:
if(objects.get(some_position).getType() == typeof(QCircle))
QCircle circle = objects.get(some_position);
else if(/* like above with QSquare */)
QSquare square = objects.get(some_position);
After you do this, you can resume using your objects like normal. But if you try accessing them from the list, you can only use the methods and variables that QShape has, as every object put in the list will be cast to it.

public Class abstract Base<T>
{
public abstract List<T>GetList();
}
then do this
public class className:Base<ObjectName>
{
public override List<T>GetList()
{
//do work here
}
}