Use a static field to count instances. : static field « Class « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Class
3. static field

using System; 
 
class CountInst {  
  static int count = 0; 
  
  // increment count when object is created 
  public CountInst() {  
    count++; 
  }  
 
  // decrement count when object is destroyed 
  ~CountInst() { 
    count--; 
  } 
  
  public static int getcount() { 
    return count; 
  } 
}  
  
class MainClass {  
  public static void Main() { 
    CountInst ob; 
 
 
    for(int i=0; i < 10; i++) { 
      ob = new CountInst(); 
      Console.WriteLine("Current count: " +  
                        CountInst.getcount()); 
    } 
 
  }  
}

Current count: 1
Current count: 2
Current count: 3
Current count: 4
Current count: 5
Current count: 6
Current count: 7
Current count: 8
Current count: 9
Current count: 10