Unity API学习之消息机制理论与应用

目录

消息机制

示例1：同一物体中不同组件之间发送消息

示例2：父与子对象之间的消息发送(BroadcastMassage)

父对象向子对象发送消息

​编辑

子对象向父对象发送消息

消息机制

在Unity中，SendMessage 方法用于在游戏对象及其所有子对象上调用指定名称的方法。这种方法可以用于在不需要知道接收方的确切类型的情况下，向游戏对象发送消息。

基本语法如下：

void SendMessage(string methodName, object value = null, SendMessageOptions options = SendMessageOptions.RequireReceiver);

methodName: 要调用的方法的名称。
value: 可选参数，要传递给方法的参数。
options: 可选参数，用于指定如何处理未找到接收方的情况。

SendMessage的传参情况分析：（以下的调用方法名以Mesage为准）

1. 在当前物体中组件名为Mesage

2. 当前物体中的其他脚本中有Mesage方法

示例1：同一物体中不同组件之间发送消息

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_Message : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        gameObject.SendMessage("Mesage");
        gameObject.SendMessage("Mesages", 1);
    }

    // Update is called once per frame
    void Update()
    {
        
    }
    //无参发出消息
    public void Mesage()
    {
        print("消息发送！！！");
    }
    //有参发出消息
    public void Mesages(int value)
    {
        print("本组件接收到消息" + value);
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Mesages : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        print("其他组件的消息发送给Mesages组件");
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Mesage : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        print("其他组件的消息发送给Mesage组件");
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class example : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        
    }
    public void Mesage()
    {
        print("消息发送！！！");
    }
    public void Mesages(int value)
    {
        print("example组件接收到消息" + value);
    }
}

注：发送消息若没有接收者则会报错，若不想要报错则需要输入如下代码

SendMessage("GetTestMsg",SendMessageOptions.DontRequireReceiver);

示例2：父与子对象之间的消息发送(BroadcastMassage)

父对象向子对象发送消息

​​using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageParent : MonoBehaviour
{
    // Start is called before the first frame update
    //BroadcastMessage向下广播，包括子对象
    void Start()
    {
        BroadcastMessage("getMesage");
    }
    public void getMesage()
    {
        print("Parent");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    /*private void Start()
    {
        SendMessageUpwards("getMesage");
    }*/
    public void getMesage()
    {
        print("Child");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild1 : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
   
    public void getMesage()
    {
        print("Child1");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild_child : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    public void getMesage()
    {
        print("Child_child");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild_child1 : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    public void getMesage()
    {
        print("Child_child1");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild_child1 : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    public void getMesage()
    {
        print("Child_child1");
    }
}

子对象向父对象发送消息

搜索范围：子对象以及上两级父对象

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageChild : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    private void Start()
    {
        SendMessageUpwards("getMesage");
    }
    public void getMesage()
    {
        print("Child");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageTest : MonoBehaviour
{
    //向自身和上级发送消息，总当前的目录地位开始
    
    public void getMesage()
    {
        print("Test");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_MessageParent : MonoBehaviour
{
    // Start is called before the first frame update
    //BroadcastMessage向下广播，包括子对象
    void Start()
    {
        /*BroadcastMessage("getMesage");*/
        
    }
    public void getMesage()
    {
        print("Parent");
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class NO8_Message : MonoBehaviour
{
    // Start is called before the first frame update
    void Start()
    {
        gameObject.SendMessage("Mesage");
        gameObject.SendMessage("Mesages", 1);
    }

    // Update is called once per frame
    void Update()
    {
        
    }
    //无参发出消息
    public void Mesage()
    {
        print("消息发送！！！");
    }
    //有参发出消息
    public void Mesages(int value)
    {
        print("本组件接收到消息" + value);
    }
    public void getMesage()
    {
        print("Message");
    }
}