initial position of drag and drop

Unity Engine
1

I have one canvas with three placeHolder and one Image over Canvas.
The Hierarchy is placeHolder’s and then Image.
I used EventTigger to put the Image with Drag and Drop over one similar placeHolder with tag “match”.
The Image is untagged.
This is the script I need to fix:

using UnityEngine;
using System.Collections;

public class ManageDragDrop : MonoBehaviour {
    Vector3 initialPosition;

    // Use this for initialization
    void Start () {
        initialPosition = gameObject.transform.position;
        print (initialPosition);
    }
   
    // Update is called once per frame
    void Update () {
   
    }
    public void Drag (){
        //store position of mouse
        GameObject.Find("Image").transform.position = Input.mousePosition;
    }
    public void Drop (){
        for (int i=1;i<=3;i++){
        GameObject placehold = GameObject.Find ("placeHolder"+i);
        float distance = Vector3.Distance (GameObject.Find ("Image").transform.position, placehold.transform.position);
        //print ("distance =" + distance);
       
            if (distance < 50)
            {
                if (placehold.CompareTag("match")==true)
                {
                    GameObject.Find ("Image").transform.position = placehold.transform.position;
                    print("match ok +"+initialPosition);
                } else {
                    GameObject.Find ("Image").transform.position = initialPosition;
                    print("not mach +-"+initialPosition);
                }
            } else {
                GameObject.Find ("Image").transform.position = initialPosition;
                print("distance > 50 "+initialPosition);
            }
        }
    }
}

The result is wrong. The image go to the left bottom screen.
One output is:
…
distance > 50 (0.0, 8.3, -4.1)
UnityEngine.MonoBehaviour:print(Object)
Why ? I don’t have -4.1 into my position of objects!!!?

2

you should use the new Interfaces for this
http://docs.unity3d.com/ScriptReference/EventSystems.IBeginDragHandler.html
http://docs.unity3d.com/ScriptReference/EventSystems.IEndDragHandler.html

the eventData that gets passed on has a postion you can read.

3

try ~
https://www.youtube.com/watch?v=2jc04S_TR5w

I saw also the docs … the default script can be something like this…

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;

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

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

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

        this.transform.position = eventData.position;
    }

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

}

The problem come with position of Vector3 … and select images into area !