Unity3d Guia

Drag an Drop UI Canvas
---------------------------

using UnityEngine;
using UnityEngine.EventSystems;

public class DragB : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
{

    public void OnBeginDrag(PointerEventData eventData)
    {
        Debug.Log("OnBeginDrag");

        this.gameObject.GetComponent<BoxCollider2D>().enabled = true;
        this.gameObject.GetComponent<SpringJoint2D>().enabled = false;

    }

    public void OnDrag(PointerEventData eventData)
    {
        Debug.Log("OnDrag");

        bool isPositionOK = this.gameObject.GetComponent<Collider>().isCollider;

        if (!isPositionOK) {
            this.transform.position = eventData.position - this.gameObject.GetComponent<MousePosition>().difPosicionesVector2;
        }

    }

    public void OnEndDrag(PointerEventData eventData)
    {
        Debug.Log("OnEndDrag");

        this.gameObject.GetComponent<BoxCollider2D>().enabled = false;

        bool isPositionOK = this.gameObject.GetComponent<Collider>().isCollider;

        if (isPositionOK) {
            this.gameObject.GetComponent<SpringJoint2D>().enabled = false;
        }
        else{
            this.gameObject.GetComponent<SpringJoint2D>().enabled = true;
        }


    }
}


Drag an Drop Sprite
---------------------------

using UnityEngine;

public class DragA : MonoBehaviour
{
    private Vector3 diferenciaPosiciones;

    void OnMouseDown()
    {
        diferenciaPosiciones = gameObject.transform.position - Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, Input.mousePosition.z));
        Cursor.visible = false;
    }

    void OnMouseDrag()
    {
        if (!this.gameObject.GetComponent<BoxCollider2D>())
        {
            Vector3 posicionRatonActual = new Vector3(Input.mousePosition.x, Input.mousePosition.y, Input.mousePosition.z);
            Vector3 posicionRatonMasDiferencia = Camera.main.ScreenToWorldPoint(posicionRatonActual) + diferenciaPosiciones;
            transform.position = posicionRatonMasDiferencia;
        }
    }

    void OnMouseUp()
    {
        Cursor.visible = true;
    }

}