如何只在协同线完成后才继续该功能？

Question

void Generate()
{
    StartCoroutine(FallDelayCoroutine());
    print("time3- " + Time.time);
}

IEnumerator FallDelayCoroutine()
{     
    print("time1- "+ Time.time);
    yield return new WaitForSeconds(3f);
    print("time2- " + Time.time);
}

输出：

时间1-0 时间3-0 时间2- 3.0146

我想要的输出是：

时间1-0 时间2-3 时间3-3

Answer 1

https://docs.unity3d.com/ScriptReference/MonoBehaviour.StartCoroutine.html的文档中似乎有一个与您所要做的几乎完全相同的示例：

IEnumerator Start()
{
    // - After 0 seconds, prints "Starting 0.0"
    // - After 2 seconds, prints "WaitAndPrint 2.0"
    // - After 2 seconds, prints "Done 2.0"
    print("Starting " + Time.time);

    // Start function WaitAndPrint as a coroutine. And wait until it is completed.
    // the same as yield WaitAndPrint(2.0);
    yield return StartCoroutine(WaitAndPrint(2.0F));
    print("Done " + Time.time);
}

// suspend execution for waitTime seconds
IEnumerator WaitAndPrint(float waitTime)
{
    yield return new WaitForSeconds(waitTime);
    print("WaitAndPrint " + Time.time);
}

关键似乎是他们的Start例程返回IEnumerator，然后使用yield return StartCoroutine(WaitAndPrint(2.0F));强制它在继续之前等待该方法。

所以对你来说等价的是：

IEnumerator Generate()
{
    yield return StartCoroutine(FallDelayCoroutine());
    print("time3- " + Time.time);
}

Answer 2

作为替代other answer，使用两个协同服务，您还可以添加一个回调，如。

IEnumerator FallDelayCoroutine(Action whenDone)
{     
    print("time1- "+ Time.time);
    yield return new WaitForSeconds(3f);
    print("time2- " + Time.time);

    whenDone?.Invoke();
}

并调用它，例如使用lambda表达式

void Generate()
{
    StartCoroutine(FallDelayCoroutine(() => {
        print("time3- " + Time.time);
    }));  
}

或者用一种方法

void Generate()
{
    StartCoroutine(FallDelayCoroutine(OnFallDelayDone));  
}

private void OnFallDelayDone()
{
    print("time3- " + Time.time);
}