在AudioGraph

Question

我编写了一个方法来获取表示音乐文件样本的float数组。我正在使用AudioGraph类。

但是当我处理AudioGraph时，我收到以下错误：

调用Dispose但在返回Method之后（下次我等待之后），不会发生错误。

代码不在UI线程上运行。在UI线程上运行不会抛出此错误。

不处理图表是另一种不抛出此错误的方法。我不喜欢这两个。

这是方法：

    private static async Task<float[]> GetAudioBuffer(IStorageFile file, IProgress<double> progress)
    {
        float[] buffer;
        int currentPart = 0;
        progress.Report(currentPart, 0);
        var createAudioGraphResult = await Windows.Media.Audio.AudioGraph.CreateAsync(new Windows.Media.Audio.AudioGraphSettings(Windows.Media.Render.AudioRenderCategory.Media));
        if (createAudioGraphResult.Status != AudioGraphCreationStatus.Success)
            CallError();
        using (var graph = createAudioGraphResult.Graph)
        {


            var result = await graph.CreateFileInputNodeAsync(file);
            if (result.Status != AudioFileNodeCreationStatus.Success)
                CallError();
            var input = result.FileInputNode;
            {


                var output = graph.CreateFrameOutputNode();
                {

                    input.AddOutgoingConnection(output);
                    TaskCompletionSource<bool> waiter = new TaskCompletionSource<bool>();
                    input.FileCompleted += (node, args) =>
                    {

                        if (!waiter.TrySetResult(true))
                            System.Diagnostics.Debug.WriteLine("This should be called only once");
                    };

                    graph.Start();

                    Task t = waiter.Task;
                    Task erg = null;
                    while (erg != t)
                    {
                        var delay = Task.Delay(500);
                        erg = await Task.WhenAny(t, delay);
                        var percentage = input.Position.TotalSeconds / input.Duration.TotalSeconds;
                        progress.Report(currentPart, percentage);
                    }

                    await waiter.Task;
                    progress.Report(currentPart, 1);
                    currentPart++;
                    graph.Stop();
                    using (var frame = output.GetFrame())
                    using (var lockedBuffer = frame.LockBuffer(Windows.Media.AudioBufferAccessMode.Read))
                    using (var refference = lockedBuffer.CreateReference())
                        unsafe
                        {
                            var memoryByteAccess = refference as IMemoryBufferByteAccess;
                            byte* p;
                            uint capacity;
                            memoryByteAccess.GetBuffer(out p, out capacity);

                            int length = (int)(capacity / sizeof(float));
                            float* b = (float*)p;
                            var channelCount = output.EncodingProperties.ChannelCount;
                            buffer = new float[length / channelCount];

                            for (int i = 0; i < length / channelCount; i++)
                            {
                                for (int j = 0; j < channelCount; j++)
                                    buffer[i] += b[i * channelCount + j];
                                buffer[i] /= channelCount;

                                var percentage = i / (double)(length / channelCount);
                                progress.Report(currentPart, percentage);
                            }
                            currentPart++;

                        }

                }
            }
        }

        return buffer;
    }