场景过渡进度条

private void Start()
    {
        LoadAScene();
    }

    public void LoadAScene()
    {
        StartCoroutine(LoadSceneAsync("SceneLogin"));
    }

    IEnumerator LoadSceneAsync(string sceneName)
    {
        AsyncOperation operation = SceneManager.LoadSceneAsync(sceneName);
        operation.allowSceneActivation = false;
        while (!operation.isDone)
        {
#if UNITY_EDITOR
            Debug.Log("Progress is :" + operation.progress);
#endif
            float progress = Mathf.Clamp01(operation.progress / 0.9f);
            progressBar.fillAmount = progress;
            loadText.text = ((int)progress * 100).ToString() + "%";
            yield return null;
            if (progressBar.fillAmount >= 0.85)
            {
                Debug.Log("跳出协程");
                yield break;
            }
        }
        operation.allowSceneActivation = true;
    }