协助“呼吸”字体大小（使用协程增加和减少）

Question

我正在尝试使“开始游戏”按钮的字体“呼吸”，使用协程增加和减少大小。

字体大小从 2.0 开始，onStart 增大到 2.20（逐渐增加 +0.01 直到达到 2.20）然后回落到 2.0（逐渐减少 -0.01 直到达到 2.0）然后重复。

我的代码在第一部分完美运行，它一直增加到 2.20，但由于某种原因，它没有从 2.20 降低到 2.0。有谁知道我做错了什么？

public class Font_Breathing : MonoBehaviour {

public TMP_Text startGame;
private float change = 0.01f;
private float delay = 0.0f;

void Start()
{
    StartCoroutine(IncreaseFont());
}

void Update()
{

}

IEnumerator IncreaseFont()
{

    while (startGame.fontSize >= 2.0f)
    {
        yield return new WaitForSeconds(delay);

        startGame.fontSize += change;

        if (startGame.fontSize >= 2.20f)
        {
            StartCoroutine(DecreaseFont());
        }
    }

}

IEnumerator DecreaseFont()
{
    while (startGame.fontSize >= 2.20f)
    {
        yield return new WaitForSeconds(delay);

        startGame.fontSize -= change;

        if (startGame.fontSize <= 2.0f)
        {
            StartCoroutine(IncreaseFont());
        }
    }

}

}

Answer 1

协程对于这个任务来说似乎有点矫枉过正（一个简单的循环器）。为什么不尝试一些更简单的东西？

例如：

public class Breathe : MonoBehaviour
{

    public TextMeshProUGUI Text;

    public float Size1;
    public float Size2;

    public AnimationCurve Ease;
    public float Speed;

    // Update is called once per frame
    void Update()
    {
        var minSize = Mathf.Min(Size1, Size2);
        var totalOffset = Mathf.Abs(Size1 - Size2);

        var factor = Ease.Evaluate(Mathf.PingPong(Time.time * Speed, 1));

        Text.fontSize = minSize + totalOffset * factor;
    }
}

---

为了具体回答您的协程问题，我似乎无法找到它的直接故障，但我会进行一些更改以排除可能性。

你有：

IEnumerator IncreaseFont() {

    // !!! This check looks like a copy-paste error from your DecreaseFont()
    //     Also, do not check for equality otherwise you will go PAST your cut-off
    while (startGame.fontSize >= 2.0f) {
        yield return new WaitForSeconds(delay);

        startGame.fontSize += change;

        //  !!! This check is redundant -> Move it outside the loop
        if (startGame.fontSize >= 2.20f) {
            StartCoroutine(DecreaseFont());
        }
    }
}

我会成功的：

IEnumerator IncreaseFont() {

    while (startGame.fontSize < 2.20f) {
        // yielding for null just waits for next frame, gives smoother animation
        yield return null; 

        startGame.fontSize += change;
    }

    // If you reach this point, the while loop has exited and can assumed that fontSize >= 2.2f
    StartCoroutine(DecreaseFont());
}

Answer 2

我认为你的逻辑是错误的，所以你总是增加你的字体试试下面，让我知道你是怎么做的。

另外我相信你需要手动告诉协程停止，否则它将无休止地运行，所以看看运行StopCoroutine

IEnumerator IncreaseFont()
{

  while (startGame.fontSize < 2.20f)
  {
    yield return new WaitForSeconds(delay);

    startGame.fontSize += change;

    if (startGame.fontSize >= 2.20f)
    {
        StartCoroutine(DecreaseFont());
        StopCoroutine(IncreaseFont());
    }
  }
}


IEnumerator DecreaseFont()
{
  while (startGame.fontSize > 2.0f)
  {
    yield return new WaitForSeconds(delay);

    startGame.fontSize -= change;

    if (startGame.fontSize <= 2.0f)
    {
        StartCoroutine(IncreaseFont());
        StopCoroutine(DecreaseFont());
    }
  }

}