Unity3D實現異步加載場景

實現異步加載場景不僅需要當前場景和目標場景，同時還需要一個中間場景實現目標場景的加載過程。

對於中間場景的構建可添加進度條（slider組件）和進度顯示（Text組件）。同時在MainCamera上掛在腳本內容如下：

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using UnityEngine.SceneManagement;

public class SceneControl
{
    public static string targetSceneName;
    public static void LoadScene(string sceneName)
    {
        targetSceneName = sceneName;
        SceneManager.LoadScene("MiddleScene");
    }
}

public class LoadScene : MonoBehaviour
{
    //將Slider組件拖入此位置
    public Slider loadingSlider;
    //將Text組件拖入此位置
    public Text loadingText;

    private float loadingSpeed = 0.4f;

    private float targetValue;

    private AsyncOperation operation;

    // Use this for initialization
    void Start()
    {
        StartCoroutine(AsyncLoading());
    }

    IEnumerator AsyncLoading()
    {
        operation = SceneManager.LoadSceneAsync(SceneControl.targetSceneName);
        //阻止當加載完成自動切換
        operation.allowSceneActivation = false;
        yield return operation;
    }

    // Update is called once per frame
    void Update()
    {
        targetValue = operation.progress;

        if (operation.progress >= 0.9f)
        {
            //operation.progress的值最大爲0.9
            targetValue = 1.0f;
        }

        if (targetValue != loadingSlider.value)
        {
            loadingSlider.value = Mathf.MoveTowards(loadingSlider.value, targetValue, Time.deltaTime * loadingSpeed);
        }
        loadingText.text = ((int)(loadingSlider.value * 100)).ToString() + "%";

        if ((int)loadingSlider.value == 1)
        {
            //允許異步加載完畢後自動切換場景
            operation.allowSceneActivation = true;
        }
    }
}

在當前場景中使用SceneControl.LoadScene(string sceneName)靜態方法就可以加載目標場景。