Async load texture from PersistentDataPath with bytes

Question

I have an issue with my texture loader, everything works fine but once the function runs Unity freezes until the files are loaded into memory. These two are the functions i use to load the textures and add them to an array.

public void LoadTextureArray(string _dirname)
    {
        var fileNames = Directory.GetFiles(Application.persistentDataPath + "/" + _dirname + "/", "*.jpg");
        source = new Texture2D[fileNames.Length];

        Array.Sort(fileNames, (s1, s2) => Path.GetFileName(s1).CompareTo(Path.GetFileName(s2)));

        int index = 0;
        foreach (var fileName in fileNames)
        {
            source[index] = LoadTextureFromPath(fileName);
            source[index].name = fileName;
            index++;
        }
    }

public Texture2D LoadTextureFromPath(string path)
    {
        if (string.IsNullOrEmpty(path))
        {
            Debug.LogError("Texture path is null or empty");
            return null;
        }

        if (!File.Exists(path))
        {
            Debug.LogError($"File not found: {path}");
            return null;
        }

        byte[] bytes = File.ReadAllBytes(path);
        Texture2D texture = new Texture2D(512, 512, TextureFormat.RGB24 , false);
        texture.LoadImage(bytes);
        Debug.Log("success");
        return texture;
    }

Now i understand i need to make it async in order for it to work on the background but honestly i have no idea how to proceed, i did read a bit on various forums but most of what i found used WWW and even though i did try some parts i was not successful.

Edit: Ok so for starters i cannot understand which of those two functions i need to make asynchronous. i found a thread which contained this code

Texture2D _content;
Material _material;

// Call this with StartCoroutine(LoadTexture(path));
IEnumerator LoadTexture(string path)
{
    // Start the asynchronous load.
    var www = new WWW("file://" + path);

    // Let the game continue running until the texture has been loaded.
    yield return www;

    // Replace current content with loaded texture.
    if (_content != null)
        Destroy(_content);
    _content = www.texture;

    // Instantiate a copy of the material, 
    // and hang onto it so we can clean up when finished with it
    if (_material == null)
        _material = GetComponent<Renderer>().material;

    _material.mainTexture = www.texture;
}

void OnDestroy()
{
    // Clean up created instances
    // (these aren't immediately garbage-collected otherwise)
    if(_material != null)
         Destroy(_material);
    if(_content != null)
         Destroy(_content);
}

but i could not make it work by replacing it with this

IEnumerator LoadTexture(string _dirname)
    {
        var fileNames = Directory.GetFiles(Application.persistentDataPath + "/" + _dirname + "/", "*.jpg");
        // Start the asynchronous load.
        var www = new WWW(fileNames.ToString());

        source = new Texture2D[fileNames.Length];

        Array.Sort(fileNames, (s1, s2) => Path.GetFileName(s1).CompareTo(Path.GetFileName(s2)));

        //Debug.Log(string.Join("\n", fileNames));

        int index = 0;
        foreach (var fileName in fileNames)
        {
            // Let the game continue running until the texture has been loaded.
            yield return www;
            source[index] = LoadTextureFromPath(fileName);
            source[index].name = fileName;
            index++;
        }
    }

and even though this works it still freezes the game abit and it takes more time to load the textures than when the game freezes, maybe i should be making the texture into a asynchronous event but i do not know how to.

Edit: by placing the yield in the foreach loop it seems to be working but is this the way it should be done?

Edit: ok so after some trial and error i think i have gotten to a decent point. this part here works in the way that it loads everything in the background without freezing the game and it loads them as fast as i would like but is it correct?

code is this

    private IEnumerator GetTextureFromPath(string _dirname)
    {
        var fileNames = Directory.GetFiles(Application.persistentDataPath + "/" + _dirname + "/", "*.jpg");
        source = new Texture2D[fileNames.Length];

        Array.Sort(fileNames, (s1, s2) => Path.GetFileName(s1).CompareTo(Path.GetFileName(s2)));

        int index = 0;

        foreach (var fileName in fileNames)
        {
            UnityWebRequest webRequest = UnityWebRequestTexture.GetTexture(fileName);

            yield return webRequest.SendWebRequest();
            while (!webRequest.isDone)
            {
                yield return null;
            }

            Debug.Log("Ends server comm");
            if (webRequest.isNetworkError || webRequest.isHttpError)
            {
                Debug.Log(webRequest.error);
            }
            else
            {
                source[index] = ((DownloadHandlerTexture)webRequest.downloadHandler).texture;
                source[index].name = fileName;
                index++;
            }
        }

    }
```

Answer 1

You don't need both

yield return webRequest.SendWebRequest();

and

while (!webRequest.isDone)
{
    yield return null;
}

You can choose one or the other. The first says "call me back when the load is 100% finished", the other says "call me back every frame, and I'll keep looping until it's finished" (useful if you wanted to put code inside that while loop that updates a progress bar or somesuch, which you're not doing here).

Otherwise, this looks fine.