Need to write only once

Hi Ramco Ramco,

One of the way is Singleton Design Pattern In C#. Below is one example for reference purpose:

using System;

// The 'Singleton' class
public class API
{
	static API instance;
    private string ApiKey;    
	private string ApiKeyTime;
	
    // Lock synchronization object
	private static object locker = new object();
	
	// Constructor (protected)
	protected API()
	{
		ApiKey = "API Key";
		ApiKeyTime = Convert.ToString(DateTime.Now.ToLongTimeString());;
	}
	
	public static API GetAPI()
	{
		// Support multithreaded applications through
		// 'Double checked locking' pattern which (once
		// the instance exists) avoids locking each
		// time the method is invoked
		if (instance == null)
		{
			lock (locker)
			{
				if (instance == null)
				{
					instance = new API();
				}
			}
		}
		return instance;
	}
	
	public string APIKey
	{
		get
		{
			return ApiKey;
		}
	}
	public string APIKeyTime
	{
		get
		{
			return ApiKeyTime;
		}
	}
}

public class Stman
{	
	public string[] Name = new string[3];
	
	public static void Main()
	{
		API api1 = API.GetAPI();
		Console.WriteLine(api1.APIKey + " and " + api1.APIKeyTime);
		
		System.Threading.Thread.Sleep(2 * 60 * 1000);
		
		API api2 = API.GetAPI();
		Console.WriteLine(api2.APIKey + " and " + api2.APIKeyTime);
	}
}

For more details:

• C# Singleton
  • https://www.dofactory.com/net/singleton-design-pattern

Hope this will help you!