Unity进度条平缓Loading

在Unity中两个场景之间的过度，为了显得不唐突，常常在期间加入第三个场景，显示进度条的过度动画,如：

private AsyncOperation async;

async.progress；

判定是否到达100%，But,Unty中progress到90%便会停止直接跳入C场景，加上如若写在Update函数中，会出现进度条的跳跃，所以为了平缓的过度必须使用到协同，该篇代码适用的是NGUI,其他则需稍微修改即可

using UnityEngine;
using System.Collections;

public class LoadingManager : MonoBehaviour {

    public UIProgressBar loadbar;
    private AsyncOperation async;
    void Start()
    {
        StartCoroutine(loadScene());
    }
  
     IEnumerator loadScene()
    {
        
        float displayProgress = 0;
        float toProgress = 0;

        
        async = Application.LoadLevelAsync("1"); //Loading Scene Name
        async.allowSceneActivation = false;
        
         while(async.progress < 0.9f)
         {

             toProgress = 90;
             while(displayProgress < toProgress)
             {
                 displayProgress++;
                 loadbar.value = displayProgress