unity-移动触摸控件在2D游戏中拖动游戏对象

Question

I wanted to find out what is the best-practice method to use for touch controls for mobile 2D games, specifically dragging a paddle for breakout/arkanoid style games. Would be surprised if there are no easy built in Unity facility to do this as I would have thought this would have been a standard feature given the popularity of mobile games. Any advice or links to tutorials, especially dragging game objects, would be greatly appreciated. Thanks.

Answer 1

My advice would be to use the unity UI features (introduced in Unity 4.6) using a script like this one :

public class DragControl : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
    private bool m_Used;
    private Vector3 m_MouseStartPosition;
    private Vector3 m_ItemStartPosition;

    public void Start()
    {
        m_Used = false;
    }

    public void Update()
    {
        if(m_Used)
        {
            GetComponent<RectTransform>().anchoredPosition = new Vector2(m_ItemStartPosition.x + (Input.mousePosition.x - m_MouseStartPosition.x), m_ItemStartPosition.y + (Input.mousePosition.y - m_MouseStartPosition.y));
            // or you can set the y value to m_ItemStartPosition.y only if you don't want the paddle to move on Y axis
        }
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        m_Used = true;
        m_MouseStartPosition = Input.mousePosition;
        m_ItemStartPosition = GetComponent<RectTransform>().anchoredPosition;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        m_Used = false;
    }
}

For this to work you have to enable the UI item raycasting (keep "Raycast Target" checked) and nothing blocking the raycast being over your item in the UI layers.

Also note that if you don't need it you can disable mutli touch input using Input.multiTouchEnabled = false; .

Answer 2

An easy solution would be to import the now standard (Unity 5?) "DragRigidbody" script and attach it to your Game Object. Just make sure your object has a RigidBody Component attached to it (which I would assume your paddle object would have already).