鼠标拖拽、屏幕坐标与世界坐标转换

using UnityEngine;
using System.Collections;
public class InputTest : MonoBehaviour {
public System.Action Drag;
void OnEnable()
{
　　Drag = DrayObject;
}
Vector3 scrPos;
Vector3 temp;
public virtual void DragObject()
{
　　scrPos = Camera.main.WorldToScreenPoint(transform.position);//将cube的坐标转换为屏幕坐标
　　temp = new Vector3(Input.mousePosition.x, Input.mousePosition.y, scrPos.z);//
　　transform.position = Camera.main.ScreenToWorldPoint(temp);//将屏幕坐标转换为世界坐标
}
void OnMouseDrag () 
{
　　if (Drag != null)
　　{
　　　　Drag();
　　}
}

//void OnMouseDrag()
//{
// transform.position = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.WorldToScreenPoint(transform.position).z)); 
//}

}