我建议使用GetAxis（“Horizontal”）和GetAxis（“Vertical”）方法，默认情况下Mapwasd和箭头键，以帮助精简您的大型if树。
下面是我以前大学项目的一个小例子。
注：“* speed * Time.deltaTime”用于在时间/帧移动时帮助转换，在这种情况下，速度只是一个乘数。

public float speed = 10.0f;
private float translation;
private float straffe;

// Use this for initialization
void Start()
{
    // turn off the cursor
    Cursor.lockState = CursorLockMode.Locked;
}

// Update is called once per frame
void Update()
{
    // Input.GetAxis() is used to get the user's input
    // You can further set it on Unity. (Edit, Project Settings, Input)
    translation = Input.GetAxis("Vertical") * speed * Time.deltaTime;
    straffe = Input.GetAxis("Horizontal") * speed * Time.deltaTime;
    transform.Translate(straffe, 0, translation);

    if (Input.GetKeyDown("escape"))
    {
        // turn on the cursor
        Cursor.lockState = CursorLockMode.None;
    }
}

Input.GetKeyDown检查您是否在该帧上按了w键。您需要Input.GetKey。它检查您是否正在按住

您应该使用GetAxis（“水平”）和GetAxis（“垂直”）;下面是我的项目默认移动的基本代码：

//movement
Rigidbody rb;
float xInput;
float yInput;
public float speed;
public float defSpeed;
public float sprint;
public bool isGrounded = true;
public float jump;

// Start is called before the first frame update

private void Awake()
{
    rb = GetComponent<Rigidbody>();
}

void Start()
{

}

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

    //Things is still can't understand
    Vector3 input = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
    float cameraRot = Camera.main.transform.rotation.eulerAngles.y;
    rb.position += Quaternion.Euler(0, cameraRot, 0) * input * speed * Time.deltaTime;

    //sprint
    if (Input.GetKeyDown(KeyCode.LeftShift)) 
    {
        speed = sprint;
    }
    else if (Input.GetKeyUp(KeyCode.LeftShift))
    {
        speed = defSpeed;
    }

    //jump
    if (Input.GetKeyDown(KeyCode.Space) && isGrounded == true)
    {
        rb.AddForce(0, jump, 0);
        //Debug.Log("Jump!");
    }

希望这有帮助：）