Development of unity script program

This is my right to Unity Check and fill the gaps in script knowledge , A lot of familiar knowledge has not been written .

Unity in C# Script specification

Inherited from MonoBehavior class

Unity All classes in scripts attached to game objects in must inherit MonoBehavior class ( Directly or indirectly ),MonoBehavior Class defines various callback methods (Start()、Update() …).

The class name must match the file name

C# The class name in the script needs to be written manually , And the class name must be the same as the file name , Otherwise, when the script is attached to the GameObject , The console will report an error

Use Awake or Start Method initialization

The code used to initialize the script must be placed in Awake or Start In the method .Awake Than Start Run earlier , Is run when the scene is loaded . and Start Method is called the first time Update or FixedUpdate Method used before .

Unity Co program in script ( coroutines ) There are different grammatical rules

Unity Medium coroutines Must be IEnumerator Return type
yield use yield return replace

using System.Collections;
using System.Collections.Generic;
using UnityEngine;// Import system package 

public class NewBehaviourScript : MonoBehaviour // Declaration class 
{
    
    private void Start()
    {
    
        StartCoroutine(SomeCoroutine());// Start the coroutines 
    }
    
    IEnumerator  SomeCoroutine()//C# coroutines 
    {
    
        yield return 0;// Wait for one frame 
        yield return new WaitForSeconds(2);// wait for 2s
    }
}

Only variables that meet certain conditions can be displayed in the property panel

Only serialized member variables can be displayed in the property panel , If the property wants to be displayed in the property panel , Then it must be public type

Try to avoid constructors

Do not initialize any variables in the constructor , Use Awake and Start Method realization . because Unity The constructor will be called automatically , It may be called by a prefab or an inactive GameObject .

Unity The singleton pattern in
Because the script file inherits MonoBehavior
Using constructors in singleton mode can have serious consequences , It will cause similar random null parameter exceptions .
To implement the singleton pattern, you cannot use constructors , But use Awake or Start Method .

in fact , There is no need to inherit from MonoBehaviour Write any code in the constructor of the class

How to be in Unity Use singleton mode in the script

public static ItemMgr instance;
void Awake()
{
    
   instance=this;
}

debugging

stay Unity in , have access to print() and Debug.Log() Output debugging information . however print() Only in Mono Used in , So generally, it is best to use Debug.Log().