按下按钮时是否具有循环功能？ Unity3d C＃

Question

So, I have an object. When I press Spin Button, I want it to spin. When I press Stop button, I want it to stop.

It spins fine when its in void Update, but when its in its own function, it does it just once. I tried using loop but still no luck. Can anyone help me please?

Code C#:

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class spin : MonoBehaviour
{
    public float speed = 500f;
    public Button starter;
    public Button stopper;

    int testing = 200;

    void Start () {

        Button btn = starter.GetComponent<Button> ();
        Button butn = stopper.GetComponent<Button> ();

        butn.onClick.AddListener(FidgetSpinnerStop);
        btn.onClick.AddListener(FidgetSpinnerStart);
    }

    void FidgetSpinnerStart ()
    {
        for (int i = 0; i < testing; i++) {
            transform.Rotate (Vector3.up, speed * Time.deltaTime);
            Debug.Log ("Test: " + i);
        }
    }

    void FidgetSpinnerStop ()
    {
        transform.Rotate (Vector3.up, Time.deltaTime);
    }
}

Thanks in advance!

Answer 1

The for loop isn't working as expected because you are not waiting for a frame. Basically, it will do all the spinning in one frame and you won't see the changes until the final spin. Waiting for a frame can the done with yield return null; and that requires a coroutine function.

This is better done with a coroutine. You can use boolean variable with a coroutine or you can just use StartCoroutine and StopCoroutine . Start coorutine that spins the Object when the start Button is clicked and then stop the coroutine when the stop Button is clicked.

public float speed = 500f;
public Button starter;
public Button stopper;
bool isSpinning = false;

IEnumerator spinnerCoroutine;

void Start()
{
    //The spin function
    spinnerCoroutine = spinCOR();

    Button btn = starter.GetComponent<Button>();
    Button butn = stopper.GetComponent<Button>();

    butn.onClick.AddListener(FidgetSpinnerStop);
    btn.onClick.AddListener(FidgetSpinnerStart);
}

IEnumerator spinCOR()
{
    //Spin forever untill FidgetSpinnerStop is called 
    while (true)
    {
        transform.Rotate(Vector3.up, speed * Time.deltaTime);
        //Wait for the next frame
        yield return null;
    }
}

void FidgetSpinnerStart()
{
    //Spin only if it is not spinning
    if (!isSpinning)
    {
        isSpinning = true;
        StartCoroutine(spinnerCoroutine);
    }
}

void FidgetSpinnerStop()
{
    //Stop Spinning only if it is already spinning
    if (isSpinning)
    {
        StopCoroutine(spinnerCoroutine);
        isSpinning = false;
    }
}

Answer 2

Following is a simple class that start and stops spinning an object using two buttons, I hope it makes a starting point of what you are trying to achieve.

public class TestSpin : MonoBehaviour
{
    public float speed = 500f;
    public Button starter;
    public Button stopper;

    bool IsRotating = false;

    void Start()
    {

        Button btn = starter.GetComponent<Button>();
        Button butn = stopper.GetComponent<Button>();

        butn.onClick.AddListener(FidgetSpinnerStop);
        btn.onClick.AddListener(FidgetSpinnerStart);
    }

    void FidgetSpinnerStart()
    {
        IsRotating = true;
    }

    void FidgetSpinnerStop()
    {
        IsRotating = false;
    }

    void Update()
    {
        if (IsRotating)
            transform.Rotate(0, speed, 0);
    }
}