Object.DontDestroyOnLoad

参数

描述

在加载新的 Scene 时，请勿销毁 Object。

The load of a new Scene destroys all current Scene objects. Call Object.DontDestroyOnLoad to preserve an Object during scene loading. If the target Object is a component or GameObject, Unity also preserves all of the Transform’s children. Object.DontDestroyOnLoad only works for root GameObjects or components on root GameObjects. Object.DontDestroyOnLoad does not return a value.

以下示例脚本便使用了 Object.DontDestroyOnLoad。该示例中的 scene1 开始播放来自 AudioSource 的背景音乐。在 scene2 加载时，音乐继续播放。使用一个按钮可以切换场景。

要实现此示例，我们创建两个新的 Scene，分别名为 scene1 和 /scene2/。打开 /scene1/，将 SceneSwap.cs 脚本添加到空的 GameObject，然后将其命名为 /Menu/。接着，将 DontDestroy.cs 添加到新的 GameObject，然后将其命名为 /BackgroundMusic/。将一个 AudioSource 添加到 BackgroundMusic - Add Component > Audio > Audio Source - 并将一个 AudioClip 导入项目中。将 AudioClip 分配给 AudioSource 的 AudioClip 字段。创建一个命名为 music 的标签，然后将其添加到 /BackgroundMusic/。切换到 /scene2/。同样，将 SceneSwap.cs 添加到新的 GameObject，然后将其命名为 scene1。保存项目。返回到 scene1 并从 Editor 中运行项目。

SceneSwap.cs 脚本：

using UnityEngine;
using UnityEngine.SceneManagement;

// Object.DontDestroyOnLoad example.
//
// Two scenes call each other. This happens when OnGUI button is clicked.
// scene1 will load scene2; scene2 will load scene1. Both scenes have
// the Menu GameObject with the SceneSwap.cs script attached.
//
// AudioSource plays an AudioClip as the game runs. This is on the
// BackgroundMusic GameObject which has a music tag.  The audio
// starts in AudioSource.playOnAwake. The DontDestroy.cs script
// is attached to BackgroundMusic.

public class SceneSwap : MonoBehaviour
{
    private void OnGUI()
    {
        int xCenter = (Screen.width / 2);
        int yCenter = (Screen.height / 2);
        int width = 400;
        int height = 120;

        GUIStyle fontSize = new GUIStyle(GUI.skin.GetStyle("button"));
        fontSize.fontSize = 32;

        Scene scene = SceneManager.GetActiveScene();

        if (scene.name == "scene1")
        {
            // Show a button to allow scene2 to be switched to.
            if (GUI.Button(new Rect(xCenter - width / 2, yCenter - height / 2, width, height), "Load second scene", fontSize))
            {
                SceneManager.LoadScene("scene2");
            }
        }
        else
        {
            // Show a button to allow scene1 to be returned to.
            if (GUI.Button(new Rect(xCenter - width / 2, yCenter - height / 2, width, height), "Return to first scene", fontSize))
            {
                SceneManager.LoadScene("scene1");
            }
        }
    }
}

DontDestroy.cs 脚本：

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

// Object.DontDestroyOnLoad example.
//
// This script example manages the playing audio. The GameObject with the
// "music" tag is the BackgroundMusic GameObject. The AudioSource has the
// audio attached to the AudioClip.

public class DontDestroy : MonoBehaviour
{
    void Awake()
    {
        GameObject[] objs = GameObject.FindGameObjectsWithTag("music");

        if (objs.Length > 1)
        {
            Destroy(this.gameObject);
        }

        DontDestroyOnLoad(this.gameObject);
    }
}