Private Constructor : We can declare a constructor private also ,this is a special instance
constructor. Classes that contain static members only are generally used
Private construtor . By setting the access modifier to
private it make clear that the constructor can not be instantiated .Generally in
designed pattern , Singleton pattern
Follow the rule ,
where class constructor is private .This make sure in a whole solution only one
instance of class can be created.
Example 1:
public class
classB
{
public int
A; // Instance field
public classB()
{
//
// TODO: Add
constructor logic here
//
}
private classB() // This is the private constructor
{
this.A = 5;
}
}
Example 2: Designed Patterns
//Create a singleton
class
public sealed
class myClass
{
private static myClass instance = null;
private static readonly object instancelock = new
object();
public myClass() //general constructor
{
}
public static
myClass Instance
{
get
{
lock (instancelock)
{
if (instance == null)
{
instance = new myClass();
}
return instance;
}
}
}
}
//Calling instance of
class
protected void Button1_Click(object
sender, EventArgs e)
{
var instance1 = myClass.Instance;
var instance2 = new myClass();
}
//only one instance of this class is possible
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