相关疑难解决方法(0)

我在 AudioKit 4.9.1 上，无法使用新的AKSequencer（替换AKAppleSequencer）播放 MIDI 文件。没有声音播放。假设 MIDI 文件和样本已正确加载，因为它们以前使用AKAppleSequencer. 还启用了背景音频模式功能。

这是相关代码：（我也尝试过AKSampler，AKAppleSampler但结果相同）

class MIDIPlayer {
    var sampler: AKSampler
    var legacySampler: AKAppleSampler
    var sequencer: AKSequencer

    init(withSfz sfz: String, orSf2 sf2: String, andMidiFile midiFile: String) {

        self.sampler = AKSampler()
        self.legacySampler = AKAppleSampler()
        try? legacySampler.loadSoundFont(sf2, preset: 0, bank: 0)
        sampler.loadSFZ(url: Bundle.main.url(forResource: sfz, withExtension: "sfz")!)

        AudioKit.output = sampler
        try? AudioKit.start()

        sequencer = AKSequencer(targetNode: sampler)
        // sequencer = AKSequencer(targetNode: legacySampler)

        let midi = AKMIDIFile(url: Bundle.main.url(forResource: midiFile, withExtension: …