Count instances of the class [duplicate]

Answer 1

 public class MyClass
    {
public  static int countinstance  =0;
MyClass(){ countinstance  ++;}
 ~ MyClass() {countinstance  --; }
    }

simple and easy get instance active by countinstance

Answer 2

Only if you implement a counting mechanism inside the constructor (increment) and finalizer (decrement). But even that will not account for instances which are really inactive (noone has any reference to them) but have not been collected yet.

Moreover, adding a finalizer to a class -- no matter how trivial -- will adversely affect performance, which is an argument against doing so.

Answer 3

Try this one:

public class MyClass
{
    public static int activeCount = 0;

    public MyClass() => activeCount++;
    ~MyClass() => activeCount--;
}


//In the main
var testClass1 = new MyClass();
var testClass2 = new MyClass();

Console.WriteLine(MyClass.activeCount);

Answer 4

Such thing is not possible but you can do something like

Note : ClassInstance can be also int value just to maintain count.

public class MyType 
{
    public static List<MyType> ClassInstance = new List<MyType>();

    public MyType() => ClassInstance.Add(this);
    public RemoveClass(MyType t)
    {
        ClassInstance.Remove(t);
        t = null;
    }

    public int ActiveCount => ClassInstance.Count;
}

Answer 5

this :

public class MyClass
{
    private static int instances = 0;

    public MyClass()
    {
        instances++;
    }

    ~MyClass()
    {
        instances--;
    }


    public static int GetActiveInstances()
    {
        return instances;
    }

}

use :

     MyClass c1 = new MyClass();
     MyClass c2 = new MyClass();

     int count = MyClass.GetActiveInstances();

Answer 6

You can try it by making a static variable for count in class and increment it in constructor and decrement in destructor.May this helps you.