Unity--drag (UI-Image, Sprite Render)

Table of contents

1.UI --- Image drag and drop

2. Sprite Renderer drag and drop

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1.UI --- Image drag and drop

The control script needs to inherit the three interfaces of IBeginDragHandler, IEndDragHandler, and IDragHandler and implement the interface methods

⚠️ Note: Add Colider 2D collision body

public class ItemContr : MonoBehaviour, IBeginDragHandler, IEndDragHandler, IDragHandler
{
    private RectTransform rectTrans;

    private void Awake()
    {
        rectTrans = GetComponent<RectTransform>();
    }

    private void OnTriggerEnter2D(Collider2D other)
    {
        //....
    }

    private void OnTriggerExit2D(Collider2D other)
    {
        //....
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        rectTrans.SetAsLastSibling();
    }

    public void OnDrag(PointerEventData eventData)
    {
        rectTrans.anchoredPosition += eventData.delta;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        rectTrans.SetSiblingIndex(1);
    }
}

2. Sprite Renderer drag and drop

⚠️Note:

1. Add Collider2D collision body

2. The Projection of Camera needs to be set to Orthographic mode

using UnityEngine;

public class ItemContr : MonoBehaviour
{
    private Camera _camera;

    private void Awake()
    {
        _camera = GameObject.FindGameObjectWithTag("camera").GetComponent<Camera>();
    }
    void Start()
    {

    }

    void Update()
    {

    }

    private void OnMouseDown()
    {
        //Debug.LogError("down");
    }

    private void OnMouseDrag()
    {
        if (_camera == null)
        {
            return;
        }
        //leftMax -2.7 rightMax 2.9   topMax 1.77  downMax -1.25
        var offsetX = _camera.ScreenToWorldPoint(Input.mousePosition).x;
        var offsetY = _camera.ScreenToWorldPoint(Input.mousePosition).y;
        transform.position = new Vector3(Mathf.Clamp(offsetX, -2.7f, 2.9f), Mathf.Clamp(offsetY, -1.25f, 1.77f), 0);
    }

    private void OnMouseUp()
    {
        //Debug.LogError("Up");
    }

    private void OnTriggerEnter2D(Collider2D collision)
    {
        //Debug.LogError("11111");
    }

    private void OnTriggerExit2D(Collider2D collision)
    {
        //Debug.LogError("2222");
    }
}