[unity, C ＃] character keyboard input steering and rotation

Operation keyboard feedback Player The displacement and turn of the protagonist

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Lemon : MonoBehaviour
{
    public float rotateSpeed  = 20f;
    //1.  Get player input ,  Move character 
    //2.  The steering problem of walking 
    //3.  Animation problems 
    private Vector3 _movement;
    private float _horizontal;
    private float _vertical;
    private Rigidbody _rigidbody;
    private Animator _animator;
    private Quaternion _rotation = Quaternion.identity;// Steering is initialized to no rotation 

    void Start()
    {
        _rigidbody = GetComponent<Rigidbody>();
        _animator = GetComponent<Animator>();
    }

    // Update is called once per frame
    void Update()
    {
        _horizontal = Input.GetAxis("Horizontal");
        _vertical = Input.GetAxis("Vertical");

    }

    private void FixedUpdate()
    {
        refreshMoveMent();
        refreshRotation();
        refreshAnimation();
    }

    private void refreshMoveMent()
    {
        // assemble 
        _movement.Set(_horizontal, 0.0f, _vertical);
        _movement.Normalize();
    }

    private void refreshRotation()
    {
        Vector3 desiredForward = Vector3.RotateTowards(transform.forward, _movement, rotateSpeed * Time.deltaTime, 0f);
        _rotation = Quaternion.LookRotation(desiredForward);
    }

    private void refreshAnimation()
    {
        bool isMoveHorizontal = !Mathf.Approximately(_horizontal, 0.0f);
        bool isMoveVertical = !Mathf.Approximately(_vertical, 0.0f);
        bool isWalking = isMoveHorizontal || isMoveVertical;
        _animator.SetBool("IsWalking", isWalking);
    }

    private void OnAnimatorMove()
    {
        // The distance the animation moves * Direction 
        _rigidbody.MovePosition(_rigidbody.position + _movement * _animator.deltaPosition.magnitude);
        _rigidbody.MoveRotation(_rotation);
    }
}