JUCE - 播放音频输入

Question

我正在学习JUCE，我正在编写一个程序，只读取声卡的输入并播放。显然这只是为了学习目的。我正在使用音频应用程序模板。这是getNextAudioBlock()函数中的代码：

void getNextAudioBlock (const AudioSourceChannelInfo& bufferToFill) override
    {

    if(true) // this is going to be replaced by checking the value of a button
    {          
        const int channel = 0;

        if(true) // this is going to be replaced too
        {
            const float* inBuffer = bufferToFill.buffer->getReadPointer(channel, bufferToFill.startSample);
            float* outBuffer = bufferToFill.buffer->getWritePointer(channel, bufferToFill.startSample);
            for(int sample = 0; sample < bufferToFill.numSamples; ++sample)
                outBuffer[sample] = inBuffer[sample];
        }
        else
        {
            bufferToFill.buffer->clear(0, bufferToFill.startSample, bufferToFill.numSamples);
        }

    }
    else
    {
        bufferToFill.buffer->clear(0, bufferToFill.startSample, bufferToFill.numSamples);
    }


}

代码非常简单：输入缓冲区中的内容直接复制到输出缓冲区。但是，我没有听到任何声音。我做错了什么？