I want to use singleton design pattern in my program. Please any one can give me a appropriate example.
Thank You.
How to implement singleton design pattern in C#?
1.96 K
26-Jan-2016
Hi Everyone,
Anupam Mishra
26-Jan-2016using System; public class Singleton { private static Singleton instance; private Singleton() {} public static Singleton Instance { get { if (instance == null) { instance = new Singleton(); } return instance; } } }This implementation has two main advantages:
Because the instance is created inside the Instance property method, the class can exercise additional functionality (for example, instantiating a subclass), even though it may introduce unwelcome dependencies.
The instantiation is not performed until an object asks for an instance; this approach is referred to as lazy instantiation. Lazy instantiation avoids instantiating unnecessary singletons when the application starts.
The main disadvantage of this implementation, however, is that it is not safe for multithreaded environments. If separate threads of execution enter the Instance property method at the same time, more that one instance of the Singleton object may be created. Each thread could execute the following statement and decide that a new instance has to be created:
if (instance == null)Various approaches solve this problem. One approach is to use an idiom referred to as Double-Check Locking. However, C# in combination with the common language run time provides a static initialization approach, which circumvents these issues without requiring the developer to explicitly code for thread safety.