我的“回归”即使没有其他代码分支，该语句也不起作用

Question

我有一个尝试创建 AudioRecord 的方法。不同的手机支持不同的采样率、通道配置和音频格式。因此该方法尝试为每个音频创建一个 AudioRecord 并返回第一个有效的。

private AudioRecord getAudioRecord() {
    for (int rate: sampleRates) {
        for (int audioFormat: audioFormats) {
            for (int channelConfig: channelConfigs) {
                String description = rate + "Hz, bits: " + audioFormat
                        + ", channel: " + channelConfig;

                Log.d(TAG, "Trying: " + description);

                int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);
                if (bufferSize == AudioRecord.ERROR
                        || bufferSize == AudioRecord.ERROR_BAD_VALUE) {
                    Log.d(TAG, "Failed: This rate/channel config/format is not supported");
                    continue;
                }

                AudioRecord recorder = new AudioRecord(AudioSource.MIC, rate, channelConfig, audioFormat, bufferSize);
                if (recorder.getState() == AudioRecord.STATE_UNINITIALIZED) {
                    Log.d(TAG, "Failed: Recorder is uninitialized");
                    continue;
                }

                Log.d(TAG, "Success: " + description);
                return recorder;
            }
        }
    }

    Log.e(TAG, "Failed all rates. Does the device have a microphone?");
    return null;
}

问题是返回记录器永远不会发生！

这是我的 logcat 输出：

在突出显示的行 (8000 / 3 / 12) 上没有错误，但也没有成功。

如果我按照下面的评论中所述不使用继续，它仍然不会返回！

private AudioRecord getAudioRecord() {
    for (int rate: sampleRates) {
        for (int audioFormat: audioFormats) {
            for (int channelConfig: channelConfigs) {
                String description = rate + "Hz, bits: " + audioFormat
                        + ", channel: " + channelConfig;

                Log.d(TAG, "Trying (2): " + description);

                int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);
                if (bufferSize != AudioRecord.ERROR && bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                    AudioRecord recorder = new AudioRecord(AudioSource.MIC, rate, channelConfig, audioFormat, bufferSize);
                    if (recorder.getState() == AudioRecord.STATE_INITIALIZED) {
                        Log.d(TAG, "Success: " + description);
                        return recorder;
                    } else {
                        Log.d(TAG, "Failed: Recorder is uninitialized");
                    }
                } else {
                    Log.d(TAG, "Failed: This rate/channel config/format is not supported");
                }
            }
        }
    }

    Log.e(TAG, "Failed all rates. Does the device have a microphone?");
    return null;
}

Answer 1

return 语句没有问题，您只是永远无法到达它，因为您的 AudioRecord 从未初始化（大多数示例都不会检查它，尽管它们可能应该检查）

作为一个简短的健全性检查，您可能需要检查您的 Manifest 文件以 < a href="https://stackoverflow.com/questions/4161666/android-audiorecord-fails-to-initialize">首先验证您是否拥有录制音频的适当权限，前提是对麦克风的访问是一项可能存在/可能不存在的硬件功能。

Answer 2

将您的函数包装在 try/catch 块中，您可能会发现某些东西导致抛出异常。