自动对焦在苹果相机应用程序示例代码中不起作用(AVFoundation AVCaptureSession)

import AVFoundation

// 创建AVCaptureSession实例
let captureSession = AVCaptureSession()

// 获取设备输入
guard let captureDevice = AVCaptureDevice.default(for: AVMediaType.video) else {
    fatalError("无法访问设备相机")
}

do {
    let input = try AVCaptureDeviceInput(device: captureDevice)
    captureSession.addInput(input)
} catch {
    fatalError("无法创建设备输入")
}

// 创建预览层
let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.frame = view.bounds
view.layer.addSublayer(previewLayer)

// 设置相机自动对焦模式
do {
    try captureDevice.lockForConfiguration()
    if captureDevice.isFocusModeSupported(.continuousAutoFocus) {
        captureDevice.focusMode = .continuousAutoFocus
    }
    captureDevice.unlockForConfiguration()
} catch {
    fatalError("无法配置相机自动对焦")
}

// 启动捕获会话
captureSession.startRunning()