相关疑难解决方法(0)

Core Audio有一个C API,可以复制你提供的内存中的一些数据.在一种情况下,我需要传入指向AudioBufferList的指针,该指针定义为:

struct AudioBufferList {
    var mNumberBuffers: UInt32
    var mBuffers: (AudioBuffer) // this is a variable length array of mNumberBuffers elements
}

UInt32标识缓冲区的数量,紧接着是实际的缓冲区.

我能成功地做到这一点:

let bufferList = UnsafeMutablePointer<AudioBufferList>.alloc(Int(propsize));
AudioObjectGetPropertyData(self.audioDeviceID, &address, 0, nil, &propsize, bufferList);

我不认识(AudioBuffer)语法,但我不认为它很重要 - 我认为括号被忽略而mBuffers只是一个AudioBuffer而且由我来做指针数学以找到第二个.

我试过这个:

let buffer = UnsafeMutablePointer<AudioBuffer>(&bufferList.memory.mBuffers);
// and index via buffer += index;
// Cannot invoke 'init' with an argument of type 'inout (AudioBuffer)'

还尝试过:

let buffer = UnsafeMutablePointer<Array<AudioBuffer>>(&bufferList.memory.mBuffers);
// and index via buffer[index];
// error: Cannot invoke 'init' with an argument of …