为什么我的脚本使我的“破折号”具有看似随机的持续时间，我该如何解决它？

问：

我是编码新手。我一直在尝试将弗兰肯斯坦的基本教程变成我自己的东西，似乎我终于碰壁了。我真的不确定是什么原因造成的，并希望得到一些帮助来解决这个问题。 在我按下破折号按钮（左移）的那一刻，我的角色会朝他面对的方向冲刺，但持续时间是随机的。我希望它保持一致并正常工作。 提前致谢！ PS：对不起，脚本太长了，它包含了与玩家移动有关的所有内容。

using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using UnityEngine;

public class CharacterController : MonoBehaviour
{
    //Player Movement
    public float speed;
    public float jumpForce;
    public Transform feetPos;
    public float checkRadius;
    public LayerMask whatIsGround;
    public float dashSpeed;
    public float startDashTime;
    public float dashCooldownTime = 2;
    private float nextFireTime = 0;


    public Animator animator;

    private Rigidbody2D rb;
    private float moveInput;
    private bool isGrounded;
    private float jumpTimeCounter;
    public float jumpTime;
    private bool isJumping;
    private float dashTime;
    public int direction;
    void Start()
    {
        animator.GetComponent<Animator>();
        rb = GetComponent<Rigidbody2D>();
        dashTime = startDashTime;
    }


    void FixedUpdate()
    {
        moveInput = Input.GetAxisRaw("Horizontal");
        if (direction < 1 )
            rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);
    }
    void Update()
    {
        // Moving
        isGrounded = Physics2D.OverlapCircle(feetPos.position, checkRadius, whatIsGround);

        if (moveInput > 0)
        {
            transform.eulerAngles = new Vector3(0, 0, 0);
            animator.SetBool("Moving", true);


        }
        else if (moveInput < 0)
        {
            transform.eulerAngles = new Vector3(0, 180, 0);
            animator.SetBool("Moving", true);
        }
        else
        {
            animator.SetBool("Moving", false);
        }
        // Jumping
        if (isGrounded == true && Input.GetKeyDown(KeyCode.Space))
        {
            animator.SetTrigger("IsJumping");
            isJumping = true;
            jumpTimeCounter = jumpTime;
            rb.velocity = Vector2.up * jumpForce;
        }

        if (Input.GetKey(KeyCode.Space) && isJumping == true)
        {
            if (jumpTimeCounter > 0)
            {
      
                rb.velocity = Vector2.up * jumpForce;
                jumpTimeCounter -= Time.deltaTime;
            }
            else
            {
                isJumping = false;
            }
        }
        if (Input.GetKeyUp(KeyCode.Space))
        {
            

            isJumping = false;
        }
        if (isGrounded == false)
        {

            animator.SetBool("Grounded", false);
            
        }
        if (isGrounded == true)
        {
            animator.SetBool("Grounded", true);
        }
        // Dashing

        if (Time.time > nextFireTime) 
        {
            if (direction == 0)
            {
                if (Input.GetKeyDown(KeyCode.LeftShift))
                {
                    UnityEngine.Debug.Log("beaners");
                    nextFireTime = Time.time + dashCooldownTime;
                    if ((transform.rotation.eulerAngles.y == 180))
                    {
                        Dashleft();

                    }
                    else
                    {
                        DashRight();
                    }

                }
            }
        }
        else
        {
            if(dashTime <= 0)
            {
                direction = 0;
                dashTime = startDashTime;
                
            }
            else
            {
                dashTime -= Time.deltaTime;

          
            }
        }
    }
    void Dashleft()
    {
        direction = 1;
        rb.velocity = Vector2.left * dashSpeed;
    }
    void DashRight()
    {
        direction = 1;
        rb.velocity = Vector2.right * dashSpeed;
    }
}