Buttons cannot be highlighted when they are selected in Unity Canvas. I only want mausehover/pointerEnter thing.

I am making a platform based 2D mobile game. Users can move their fingers without take off from the screen. So I don't need Pressed and Selected states.

The alpha of the button will be maximum when it is in PointerEnter state, and the alpha of the button will be like 100/255 when it is in PointerExit state. That's it.

Tried something like change Transition to Sprite Swap; like trying Toggle component instead of Button in Unity. But I'm stuck, I don't know solution is.

CodePudding user response：

You could not use the Button component at all and rather have a simple component and "do it all yourself" - as you say using the IPonterEnterHandler / IPointerExitHandler interfaces

public class HoverButton : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler, IPointerClickHandler
{
    [SerializeField] private Image image;
    [SerializeField] private Color normal = new Color(1f, 1f, 1f, 0.4f);
    [SerializeField] private Color hover = Color.white;

    // event called when pointer enters this button
    public UnityEvent onEnter;
    // event called once a frame while the button stays hovered
    public UnityEvent whileHovered;
    // event called when pointer exits this button
    public UnityEvent onExit;

    // wasn't sure if you still want fade effects 
    // if not you can of course skip all related stuff and just hard assign the image.color
    [SerializeField][Min(0f)] private float fadeDuration = 0.2f;
    
    private Coroutine currentRoutine;
    private float currentFactor;

    private void Awake()
    {
        if(!image) image = GetComponent<Image>();
    }

    private IEnumerator Fade(bool isHover)
    {
        var targetColor = isHover ? hover : normal;
        var targetFactor = isHover ? 1f : 0f;

        if(fadeDuration > 0f)
        {
            var step = (isHover ? (1 - currentFactor) : currentFactor) / fadeDuration;

            while(!Mathf.Approximately(currentFactor, targetFactor))
            {
                currentFactor = Mathf.MoveTowards(currentFactor, targetFactor, step * Time.deltaTime);
                image.color = Color.Lerp(normal, hover, currentFactor);
                whileHovered.Invoke();
                yield return null;
            }
        }

        currentFactor = targetFactor;
        image.color = targetColor;

        // continue calling the whileHovered every frame
        while(true)
        {
            whileHovered.Invoke();
            yield return null;
        }
    }

    public void OnPointerEnter(PointerEventData pointerEventData)
    {
        if(currentRoutine != null) StopCoroutine(currentRoutine);

        currentRoutine = StartCoroutine(Fade(true));

        onEnter.Invoke();
    }

    public void OnPointerExit(PointerEventData pointerEventData)
    {
        if(currentRoutine != null) StopCoroutine(currentRoutine);

        currentRoutine = StartCoroutine(Fade(false));

        onExit.Invoke();
    }
}