unity-singleton mode

Unity Singleton Pattern-Directory

What is the singleton pattern

Advantages

Disadvantages

Example

What is singleton mode

Singleton pattern is a common software design pattern, which means that a class has only one instance and provides a globally accessible property to access this singleton.

So before using the singleton pattern, we have to think about how to get an instance?If we want to access another script in a C# script, we need to create it when we get the instance. If we want to call it in multiple scripts, the creation and destruction of instance objects will be very frequent, which will take up a lot of system resources.

Singleton can solve this problem. Singleton mode can directly create an instance to call globally, which is quite a globally shared class.Save system resources.

Benefits

• Can effectively reduce memory overhead, singleton mode has only one instance, avoid frequent creation and destruction of objects, save system resources
• Easy to call and share resources because a globally shared class is created
• Avoid resource duplication, such as a file write operation, since only one instance exists in memory, avoid simultaneous write operations to the same resource file

Disadvantages

• Singleton mode generally has no interface, it is very difficult for him to achieve extension
• All classes can be accessed, which will cause confusion in class relationships
• The code is bloated, reducing the readability and reliability of the code

Note: In the project, the dependency of the class on the singleton class should be reduced and the code quality should be improved

Script example

GameManager usually uses singleton mode in games. Let's use it as an example to show how to implement singleton mode in C# script

using System.Collections;using System.Collections.Generic;using UnityEngine;public class GameManager : MonoBehaviour{public static GameManager instance;private void Awake(){if(instance!=null){Destroy(gameObject);}instance = this;}}