unity如何同时实现键鼠控制视角与鼠标拖拽物体进行移动。

我在unity写了两个C#脚本，一个是通过键盘鼠标控制移动的，另一个是通过鼠标拖拽移动物体的。但是当通过键盘鼠标控制移动的脚本运行之后，就无法在通过鼠标拖拽移动物体。Unity也没有报错。代码如下，请各位不吝赐教：

using UnityEngine;
//此脚本功能为：通过鼠标拖拽移动游戏场景内的物体
public class DragObject : MonoBehaviour
{
    private bool dragging = false;
    private Vector3 screenPoint;
    private Vector3 offset;

    void OnMouseDown()
    {
        // 当鼠标点击物体时记录屏幕坐标
        screenPoint = Camera.main.WorldToScreenPoint(gameObject.transform.position);
        offset = gameObject.transform.position - Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z));
        dragging = true;
    }

    void OnMouseUp()
    {
        // 当鼠标释放时停止拖拽
        dragging = false;
    }

    void OnMouseDrag()
    {
        // 当鼠标拖拽时更新物体位置
        if (dragging)
        {
            Vector3 mousePosition = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z);
            gameObject.transform.position = Camera.main.ScreenToWorldPoint(mousePosition) + offset;
        }
    }
}

```c#
using UnityEngine;
/*该程序功能为：通过鼠标键盘实现第一人称视角控制*/

public class FirstPersonController : MonoBehaviour
{
    public float moveSpeed = 5.0f;
    public float lookSpeed = 2.0f;
    public float lookXLimit = 45.0f;

    private float rotationY;
    private float rotationX;
    private CharacterController controller;

    void Start()
    {
        Cursor.lockState = CursorLockMode.Locked;
        controller = GetComponent<CharacterController>();
    }

    void Update()
    {
        if (Input.GetMouseButton(1))
        {
            rotationX -= Input.GetAxis("Mouse Y") * lookSpeed;/*rotationX-与rotationY+中的减号和加号决定鼠标移动方向最终朝向的视野*/
            rotationY += Input.GetAxis("Mouse X") * lookSpeed;
            rotationX = Mathf.Clamp(rotationX, -lookXLimit, lookXLimit);
            transform.localRotation = Quaternion.Euler(rotationX, rotationY, 0);
            transform.GetChild(0).localRotation = Quaternion.Euler(0, rotationY, 0);
        }

        float moveX = Input.GetAxis("Horizontal");
        float moveZ = Input.GetAxis("Vertical");

        Vector3 moveDir = new Vector3(moveX, 0, moveZ).normalized;
        moveDir = transform.TransformDirection(moveDir);
        moveDir.y = 0;
        controller.Move(moveDir * moveSpeed * Time.deltaTime);
    }
}

```