协程导致统一崩溃

Question

我在我的脚本中添加了以下函数，它导致 unity 崩溃。

public void AddCurrentFrameToVideo()
{
    _addFrameFunctionHasBeenCalled = true;

    using (var encoder = new MediaEncoder(encodedFilePath, videoAttr, audioAttr))
    using (var audioBuffer = new NativeArray<float>(sampleFramesPerVideoFrame, Allocator.Temp))
    {

        IEnumerator SetFrame()
        {
            yield return new WaitForSeconds(0.3f);
            encoder.AddFrame(tex);
            encoder.AddSamples(audioBuffer);
            if (recordingButtonHasBeenPressed)
            {
                yield return StartCoroutine(SetFrame());
            }
            else
            {
                yield return null;
                yield break;
            }

        }

        IEnumerator mycoroutine;
        mycoroutine = SetFrame();

        if (recordingButtonHasBeenPressed)
        {
            StartCoroutine(mycoroutine);
        }
        else
        {
            StopCoroutine(mycoroutine);
        }

    }

}

我在 Update 函数的 if 语句中调用了这个函数。见：

void Update()
{
    _currentsframe = Time.frameCount;

    if (recordingButtonHasBeenPressed)
    {
        if (!videoBasicFileHasBeenCreated)
        {
            CreateVideoBasicFile();
        }

        if (!_addFrameFunctionHasBeenCalled)
        {
            AddCurrentFrameToVideo();
        }

    }

}

我还通过按钮 OnClick() 在另一个脚本中控制了 recordingButtonHasBeenPressed 变量。见：

public void RecordVideo_OnClick()
{
    if (videoIsRecording)
    {
        videoIsRecording = false;
        videoRecordButton.image.sprite = videoButtonIsNotRecordingSprite;

        _myRecorderSc.recordingButtonHasBeenPressed = false;
        _myRecorderSc.videoBasicFileHasBeenCreated = false;
    }
    else
    {
        videoRecordButton.image.sprite = videoButtonIsRecordingSprite;
        _myRecorderSc.recordingButtonHasBeenPressed = true;
        _myRecorderSc.videoBasicFileHasBeenCreated = false;
        videoIsRecording = true;
    }
}

我不知道为什么它会崩溃。我不认为这是一个无限循环。我还测试了 DO-While 循环而不是使用 Croutine。见：

    using (var encoder = new MediaEncoder(encodedFilePath, videoAttr, audioAttr))
    using (var audioBuffer = new NativeArray<float>(sampleFramesPerVideoFrame, Allocator.Temp))
    {
        do
        {
                encoder.AddFrame(tex);
                encoder.AddSamples(audioBuffer);
        } while (recordingButtonHasBeenPressed);
    }

它也会导致 unity 崩溃。

我该怎么办？怎么了？

Answer 1

这个

    IEnumerator SetFrame()
    {
        yield return new WaitForSeconds(0.3f);
        encoder.AddFrame(tex);
        encoder.AddSamples(audioBuffer);
        if (recordingButtonHasBeenPressed)
        {
            yield return StartCoroutine(SetFrame());
        }
     }

是一个递归调用，您再次 yield return 相同的例程（在内部再次 yield return 相同的例程等）所以它会等到所有嵌套子例程完成 => 所以在某个时候你会得到一个 Whosebug！

这绝对是一个封闭的永无止境的while循环

using (var audioBuffer = new NativeArray<float>(sampleFramesPerVideoFrame, Allocator.Temp))
{
    do
    {
            encoder.AddFrame(tex);
            encoder.AddSamples(audioBuffer);
    } while (recordingButtonHasBeenPressed);
}

在循环中 recordingButtonHasBeenPressed 的值将 永远不会 改变并且 Unity/your 应用程序立即永远冻结！

你想要做的是像

这样的协程

IEnumerator SetFrame()
{
    // initially wait once
    yield return new WaitForSeconds(0.3f);

    // simply continue to execute the routine until the record shall be stopped
    while(recordingButtonHasBeenPressed)
    {
        encoder.AddFrame(tex);
        encoder.AddSamples(audioBuffer);

        // yield the next frames for 0.3 seconds before checking 
        // recordingButtonHasBeenPressed again
        yield return new WaitForSeconds(0.3f);
    }
}

你甚至不需要主动阻止它。您需要做的就是启动它，然后为了中断它只需将 recordingButtonHasBeenPressed 设置为 false。

事件驱动

现在一般来说，而不是使用 Update 和多个控制器标志 bool，一旦这里调用一个方法，你似乎立即再次重置我宁愿制作整个代码 事件驱动 并在调用按钮时调用一次。这将防止意外地出现并发例程运行，并使整个过程更易于阅读和维护。

我不知道你的完整代码，但它可能看起来像

public void RecordVideo_OnClick()
{
    // invert the toggle flag
    videoIsRecording = !videoIsRecording;

    // depending on the new flag value chose the sprite
    videoRecordButton.image.sprite = videoIsRecording ? videoButtonIsRecordingSprite : videoButtonIsNotRecordingSprite;

    if (!videoIsRecording)
    {
        _myRecorderSc.StopRecording();
    }
    else
    {
        _myRecorderSc.StartRecoring();
    }
}

然后在记录器脚本中你只需要

public void StartRecording()
{
    if(!recording)
    {
        StartCoroutine(RecorderRoutine);
    }
}

public void StopRecording()
{
    recording = false;
}

// flag to interrupt running record
private bool recording;

private IEnumerator RecorderRoutine()
{
    // Just in case prevent concurrent routines
    if(recording) yield break;
    recording = true;

    // initialize your file
    CreateVideoBasicFile();    

    // initially wait once
    yield return new WaitForSeconds(0.3f);

    using (var encoder = new MediaEncoder(encodedFilePath, videoAttr, audioAttr))
    using (var audioBuffer = new NativeArray<float>(sampleFramesPerVideoFrame, Allocator.Temp))
    {
        // simply continue to execute the routine until the record shall be stopped
        while(recording)
        {
            encoder.AddFrame(tex);
            encoder.AddSamples(audioBuffer);

            // yield the next frames for 0.3 seconds before checking 
            // recordingButtonHasBeenPressed again
            yield return new WaitForSeconds(0.3f);
        }
    }

    recording = false;
}

协程导致统一崩溃

Coroutine causes crash in unity

c#

crash

coroutine

unity3d