Do while doesnt work with async.progress

I want to load my scene when async.progress is 0.9,but first of all,i want to run my loading screen text at least once,but i dont know why it doesnt work

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3. using System.Collections;
4.  
5. public class LoadScreenScript : MonoBehaviour
6. {
7.     public Text DoYouKnow;
8.     public Text loadingText;
9.  
10.  
11.     public int imageNumber;
12.     public float letterPause;
13.  
14.     public string sceneToLoad;
15.     string messageToAnimate;
16.     // Use this for initialization
17.  
18.     void Start ()
19.     {
20.         messageToAnimate = ".......";
21.         loadingText.text = "Loading";
22.  
23.         changeDoYouKnowText ();
24.         StartCoroutine (LoadingScreen ());
25.     }
26.    
27.     // Update is called once per frame
28.     void Update ()
29.     {
30.        
31.     }
32.  
33.     void changeDoYouKnowText()
34.     {
35.         imageNumber = Random.Range (1, 5);
36.         Debug.Log (imageNumber);
37.         if (imageNumber == 1)
38.             DoYouKnow.text = "hello mikel";
39.         else if (imageNumber == 2)
40.             DoYouKnow.text = "hello erick";
41.         else if (imageNumber == 3)
42.             DoYouKnow.text = "hello kevin";
43.         else if (imageNumber == 4)
44.             DoYouKnow.text = "hello world";
45.     }
46.  
47.     IEnumerator LoadingScreen ()
48.     {
49.         AsyncOperation async = Application.LoadLevelAsync (sceneToLoad);
50.         Debug.Log(async.progress);
51.         async.allowSceneActivation = false;
52.         do{
53.             foreach (char letter in messageToAnimate.ToCharArray())
54.             {
55.                 loadingText.text += letter;
56.                 yield return 0;
57.                 yield return new WaitForSeconds (letterPause);
58.             }
59.             loadingText.text = "Loading";
60.             Debug.Log(async.progress);
61.         }while(async.progress<0.9);
62.         async.allowSceneActivation = true;
63.     }
64.  
65.  
66. }
67.  

 

It is quite possible that your scene loads instantly, so it never manages to update your text. You can try to fake loading though, like yield 1 second to animate text, then try to LoadLevelAsync() and do the loop. That way, if your scene loads instantly you will still display animated text once, as well as cover huge scenes that take some time to load.

Hope it helps!