用鼠标去控制物体移动的方法

using UnityEngine;
using System.Collections;

public class hero : MonoBehaviour
{
    private bool isMouseDown = false;
    private Vector3 lastMousePosition=Vector3.zero;
  
    void Update () {
                PlayerControler();
    }

    public void PlayerControler()
    {

        //将像素位置转换成世界坐标轴的位置
        //Camera.main.ScreenToWorldPoint(Input.mousePosition);


        //检测鼠标是否按下
        if (Input.GetMouseButtonDown(0))
        {
            isMouseDown = true;
            print(isMouseDown);
        }
        if (Input.GetMouseButtonUp(0))
        {
            isMouseDown = false;
            lastMousePosition=Vector3.zero;//将最后一次点击的位置清零
        }
        if (isMouseDown)
        {
            if (lastMousePosition!=Vector3.zero)
            {
                //得到点击位置与飞机停留位置的偏移值
                Vector3 offset = Camera.main.ScreenToWorldPoint(Input.mousePosition) - lastMousePosition;
                //当前脚本所挂载的物体的位置就等于偏移值+原先停留的位置实现移动
                transform.position = offset +transfom.position;
            }
            //让停留位置等于点击位置
            lastMousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            print(lastMousePosition);
            CheckPosition();
        }
    }
    //检测物体边界的方法
    public void CheckPosition()
    {
        Vector3 pos=transform.position;
        float x = pos.x;
        float y = pos.y;
        if (x<=-2.8f)
        {
            x = -2.8f;
        }
        if (x >= 2.8f)
        {
            x = 2.8f;
        }
        if (y <= -5.1f)
        {
            y = -5.1f;
        }
        if (y >= 5.1f)
        {
            y = 5.1f;
        }
        transform.position=new Vector3(x,y,0);
    }
}