Unity 异步加载场景

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;
using Babybus;

public class LoadingManager : MonoBehaviour
{
    public static int               nextSceneId = -1;

    public int                      sceneId = -1;

    public GameObject               loadingSceneCanvas;

    private IEnumerator Start()
    {
        //yield return new WaitForSeconds(1);
        BabySystem.ShowAdView();
        yield return null;


        sceneId = sceneId < 0 ? nextSceneId : sceneId;
        if (sceneId == -1)
            sceneId = 0;

        var ao = SceneManager.LoadSceneAsync(sceneId);
        ao.allowSceneActivation = false;

        while (ao.progress < 0.9f)
        {
            yield return null;
        }
        yield return null;

        ao.allowSceneActivation = true;
    }

}

大概意思是这样，如果allowSceneActivation 为false , 进度条最终将停在0.9，然后IsDone 一直保存false，直到allowSceneActivation 被设置为true，可以**新场景。一般和LoadLevelAsync 与 LoadLevelAdditiveAsync组合使用。

注意加入上面那个0.9 改成大于0.9它就一直在while这个循环内，也就是不会跳转。

https://docs.unity3d.com/ScriptReference/AsyncOperation.html