（unity和C#）Event

作者: 叫我颜先生 | 来源:发表于2018-09-18 18:41 被阅读0次

（unity和C#）Event
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简介

实例

简单调用

using UnityEngine;

public class DelegateExample : MonoBehaviour {
    //Step1. 定义类型----为Delegate定义一种函数原型
    public delegate void MyDelegate(int args);
    //Step2. 声明变量----声明一个Delegate变量
    public MyDelegate myDelegate;

    private void Start()
    {
        //Step3. 变量赋值----引用Delegate变量实现相应的函数
        myDelegate = PrintNum;
        myDelegate(5);
    }

    public void PrintNum(int num)
    {
        print("Print number: " + num);
    }
}

C# Event

把Event想象成一个视频作者，并且他还具有一大堆热情的粉丝，每天都在等待新视频的发布。为了在第一时间收看到新发布的视频，粉丝们大多会选择订阅视频作者，这样作者更新时你就会收到一条即时消息。event只负责告诉每个函数什么时候被调用，这些函数到底干了什么，event并不关心

//Idol.cs 广播消息 定义的event相当于源头，只要调用了该事件，都会引起注册该事件的人调用相应的注册方法
public class Idol : MonoBehaviour {
    public delegate void IdolBehaviour(string behaviour);
    public static event IdolBehaviour IdolDoSomethingHandler;

    private void Start()
    {
        //Idol 决定搞事了, 如果他还有粉丝的话, 就必须全部都通知到
        if (IdolDoSomethingHandler != null)
        {
            IdolDoSomethingHandler("Idol give up writing.");
        }
    }
}

//SubscriberA.cs  订阅消息 很早注册订阅了，当event发送了，那么就会调用对应方法
public class SubscriberA : MonoBehaviour {
    private void OnEnable()
    {
        //注册事件 相当于偶像突然有什么事件了，就会立即知道
        Idol.IdolDoSomethingHandler += LikeIdol;
    }

    //取消注册 
    private void OnDisable()
    {
        Idol.IdolDoSomethingHandler -= LikeIdol;
    }

    /// 粉丝A是一个脑残粉
    public void LikeIdol(string idolAction)
    {
        print(idolAction + " I will support you forever!");
    }
}

Unity Event

主要是可以拖拽很方便，用Serializable序列化IdolEvent，这样可以在Editor中显示

//Idol.cs 需要的event直接继承自UnityEvent
using UnityEngine;
using UnityEngine.Events;

//使用Serializable序列化IdolEvent, 否则无法在Editor中显示
[System.Serializable]
public class IdolEvent : UnityEvent<string> {

}

public class Idol : MonoBehaviour {
    public IdolEvent idolEvent;
    private void Start()
    {
        //Idol 广播消息
        if (idolEvent == null)
        {
            idolEvent = new IdolEvent();
        }
        idolEvent.Invoke("Idol give up writing.");
    }
}

//SubscriberA.cs  如果通过拖拽，只需要写个方法即可
//不通过拖拽 也可以注册 Addlistener
using UnityEngine;
public class SubscriberB : MonoBehaviour {
    public Idol myIdol;
    private void OnEnable()
    {
        //注册事件
        myIdol.idolEvent.AddListener(HateIdol);
    }

    private void OnDisable()
    {
        myIdol.idolEvent.RemoveListener(HateIdol);
    }

    public void HateIdol(string idolAction)
    {
        print(idolAction + " I will hate you forever!");
    }
}

C# Action+Unity Action

其实是封装好的委托

//Data.cs 定义委托，值改变给委托
using UnityEngine;
using System.Collections;

public class Data {
  public System.Action<int, int> onDataChange;
    public UnityAction<int, int> onDataChange1;

    public int blood { get; set; }
    public int blue { get; set; }

    public Data()
    {

    }

    public void SetData(int blood, int blue)
    {
        this.blood = blood;
        this.blue = blue;
        onDataChange(this.blood, this.blue);
        onDataChange1(this.blood, this.blue);
    }
}

//Test.cs 可以UI显示  
public class Test : MonoBehaviour
{
    private Data _Data;
    private void Start()
    {
        _Data = new Data();
        _Data.onDataChange += ChangeView;
        _Data.onDataChange1 += ChangeView;
    }

    private void ChangeView(int a,int b)
    {
        Debug.LogError(a);
    }

    void Update()
    {
        _Data.SetData(1, 2);
    }
}

Unity Event+Action

action是委托，可以注册很多方法
event是事件，能够注册方法，也能action
event的Invoke()方法可以一次性调用所有UnityAction

//不带参数UnityEvent不是抽象类，可以直接实例化
using UnityEngine;
using System.Collections;
using UnityEngine.Events;
 
public class UnityActionAndEvent : MonoBehaviour
{
    public UnityAction action;
    public UnityEvent myEvent = new UnityEvent();
 
    void Start()
    {
        action = new UnityAction(MyFunction);
        action += MyFunction2;
        myEvent.AddListener(action);
    }
 
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.P))
        {
            myEvent.Invoke();
        }
    }
 
    public void MyFunction()
    {
        print("Hello: ");
    }
 
    public void MyFunction2()
    {
        print("Hello2: ");
    }
}

//带参数UnityEvent是抽象类，需要自己声明一个类
public class MyEvent:UnityEvent<int>{}

public class UnityActionWithParameter : MonoBehaviour {
    public MyEvent myEvent = new MyEvent();
    public UnityAction<int> action;
 
    void Start () {
        action= new UnityAction<int>(MyFunction);
        action += MyFunction2;
        myEvent.AddListener(action);
    }  
 
    void Update () {
        if(Input.GetKeyDown(KeyCode.A))
        {
            myEvent.Invoke(10);
        }
    }
 
    public void MyFunction(int i)
    {
        print (i);
    }
    public void MyFunction2(int i)
    {
        print(i*2);
    }
}

其他事件（button.onClick等，通过Addlistener添加Action，Action可以注册多个方法）

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;

public class UnityActionExample : MonoBehaviour
{
    Button m_AddButton;
    Renderer m_Renderer;

    private UnityAction m_MyFirstAction;
    float m_MyNumber;

    void Start()
    {
        m_AddButton = GetComponent<Button>();
        m_Renderer = GetComponent<Renderer>();

        m_MyFirstAction += MyFunction;
        m_MyFirstAction += MySecondFunction;

        m_AddButton.onClick.AddListener(m_MyFirstAction);
    }

    void MyFunction()
    {
        m_MyNumber++;
        Debug.Log("First Added : " + m_MyNumber);
    }

    void MySecondFunction()
    {
        m_Renderer.material.color = Color.blue;
        Debug.Log("Second Added");
    }
}