Load Scene Asynchronously - loading bar

I make a Player that read a XML file and create dinamicaly the scene (camera, objects, light, materials, ecc)
(in HDRP)
All works ok but when i load the scene the screen is black for many seconds

My problem is: how to show a progress bar while parsing the XML file in C#?
for now (testing) i use a simple button and a static variable
The big problem is that the SceneManager.LoadSceneAsync ending before execution of my script (the main loop in the AWAKE event) that i have attached on a empty gameobject in scene to load

on the button onClick:

AsyncOperation operation = SceneManager.LoadSceneAsync(sceneIndex);
Text mytext = thebutton.GetComponent<Text>();
while (!operation.isDone)
{
mytext.text = "Test " + StaticValues.myprogress;
yield return null;
}

I created 2 scene: the first is the main scene with a canvas and one button (for testing), the second one with the parsing script attached to one empty gameobject.
I make also a script with a static variable:

public class StaticValues : MonoBehaviour
{
public static int myprogress = 0;

}

when i click on the button in the first scene the follow script start:

public GameObject thebutton;

public void LoadLevel(int sceneIndex)
{
StartCoroutine(LoadAsynchronously(sceneIndex));
}
IEnumerator LoadAsynchronously(int sceneIndex)
{
StaticValues.myprogress = 0;
AsyncOperation operation = SceneManager.LoadSceneAsync(sceneIndex);
Text mytext = thebutton.GetComponent<Text>();
while (!operation.isDone)
{
mytext.text = "Test " + StaticValues.myprogress;
yield return null;
}
}

In the scene loaded by LoadSceneAsync in one empty GameObject i attached my parsing script:

void Awake()
{
myCaricaScena(1);
}
bool myCaricaScena(int numero_scena)
{
....

StreamReader reader = new StreamReader(NomeFileXML);
while ((line = reader.ReadLine()) != null)
{
StaticValues.myprogress++;

... create mesh and other objects

I can't show StaticValues.myprogress in the button because operation.isDone = true before
myCaricaScena(1) start;

Is it possible to solve this problem?

 

I think you will need to create an empty scene called preloader with a preloader component. And then show it loading while the next scene is loading. Because it will have a single game object it won't take more than a second to load.

while (!operation.isDone)
{
// You can increase the localScale of progress bar game object at this place
progressbar.transform.localScale = new Vector3( x_val++, y_flt,z_flt) ;
yield return null;
}

 

I already created an empty scene with a preloader component (script attached to a button)
and the main scene is in the second scene.
the problem is that i read the objects from an external file (XML) in the second scene, create GameObjects at runtime (may be 100 objects or more).
While i read the lines of external file XML i have the progress variable in my hands (i know how many objects are and the current one) but i dont know how write that on the button.

 

... or must i create a
third preload scene between my two scene ... I go to work !!!

 

Not work !!!(may be i don't understand Unity ...)
in scene 1 where i click the button that load the scene 2 and wait (SceneManager.LoadSceneAsync...)
OnDisable() execute before Awake() in the scene 2.
My loop that read XML is in Awake(), so its IMPOSSIBLE for me write on Button in scene 1
Or not?
Unity is so bad? I only 3 weeks on Unity, this is my first big problem with it

 

I solved by StartCoroutine(myCaricaScena()); in AWAKE

For testing i make a Canvas with a Text component and add one script:
...
void Update()
{
if (lastProgress != StaticValues.myprogress)
{
lastProgress = StaticValues.myprogress;
MyText2.text = "Test " + StaticValues.myprogress;
}
}

in myCaricaScena()
in the loop where i read the lines of XML and create objects i execute the
yield return null;
(only fiew times regardless the positions in the file )
and set the variable StaticValues.myprogress

I must create all the objects with SetActive(false)
and reactivate at the and of the loop
maybe i understood StartCoroutine

It was very symple

This is my scene described in the xml showed by player without changing anytings by the editor