问将Vector3转换为单位浮点数

EN

using UnityEngine;
using System.Collections;
public class GetPosition : MonoBehaviour
{
    Vector3 dragStartPosition;
    float dragStartDistance;
    float[] Xfloat;

    void OnMouseDown()
    {
        dragStartPosition = transform.position;
        dragStartDistance = (Camera.main.transform.position - transform.position).magnitude;
    }

    void Update()
    {
    }

    void OnMouseDrag()
    {
            Vector3 worldDragTo = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, dragStartDistance));
            transform.position = new Vector3(worldDragTo.x, dragStartPosition.y, dragStartPosition.z);
            new Vector3(worldDragTo.x, dragStartPosition.y, dragStartPosition.z);
            float Newpos = ;
    }

    void OnMouseUp()
    {
    }

}