C#

class MyClass
{
   ...


   MyForm m_frm;

   public void OnButton1Click(object sender, EventArgs e)
   {
      if (m_frm == null)
      {
         m_frm = new MyForm();
         m_form.Show();
      }
   }
}

kinnuP wrote:

u

kinnuP wrote:

r

kinnuP wrote:

place u r asp.net questions in asp.net form not in C#

Christian Graus wrote:

A private constructor and a create method. A static boolean flag that starts as false, is set true by the Create method, and returns null once that flag is true.

public SingletonClass
{
    private static SingletonClass onlyInstance;
 
    // Private constructor - only this class can instantiate itself
    private SingletonClass()
    {
    }
 
    public SingletonClass Instance
    {
        get
        {
            if (onlyInstance == null)
                onlyInstance = new SingletonClass();
            return onlyInstance;
        }
    }
 
    // Do your stuff here.
}