SWIFT 3：使用AVCapturePhotoOutput捕获照片（需要另一组眼睛来查看代码，为什么这不起作用？）

Question

我有一个自定义相机，将AVCapturePhotoCaptureDelegate添加到类中，以下代码捕获一个静止图像图片：

奥特莱斯，变量和常量

@IBOutlet weak var cameraPreview: UIView! 
@IBOutlet wear var takePhotoPreview: UIImageView! 

private var cameraView: AVCaptureVideoPreviewLayer! 
private var camera: AVCaptureDevice! 
private var cameraInput: AVCaptureDeviceInput! 
private var cameraOutput: AVCapturePhotoOutput! 
private var photoSampleBuffer: CMSampleBuffer? 
private var previewPhotoSampleBuffer: CMSampleBuffer? 
private var photoData: Data? = nil 

private let cameraSession = AVCaptureSession() 
private photoOutput = AVCapturePhotoOutput() 

设置摄像机会议

private func createCamera() { 
    cameraSession.beginConfiguration() 
    cameraSession.sessionPreset = AVCaptureSessionPresetPhoto 
    cameraSession.automaticallyConfiguresCaptureDeviceForWideColor = true 

    // Add Camera Input 
    if let defaultCamera = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back).devices { 
     camera = defaultCamera.first 
     do { 
      let cameraInput = try AVCaptureDeviceInput(device: camera) 
      if cameraSession.canAddInput(cameraInput) { 
       cameraSession.addInput(cameraInput) 
       print("Camera input added to the session") 
      } 
     } catch { print("Could not add camera input to the camera session") } 
    } 

    // Add Camera View Input 
    if let cameraView = AVCaptureVideoPreviewLayer(session: cameraSession) { 
     cameraView.frame = cameraPreview.bounds 
     cameraView.videoGravity = AVLayerVideoGravityResizeAspectFill 
     cameraView.cornerRadius = 12.0 
     cameraPreview.layer.addSublayer(cameraView) 
     print("Camera view created for the camera session") 
    } else { print("Could not create camera preview") } 

    // Add Photo Output 
    let cameraPhotoOutput = AVCapturePhotoOutput() 
    if cameraSession.canAddOutput(cameraPhotoOutput) { 
     cameraSession.addOutput(cameraPhotoOutput) 
     cameraPhotoOutput.isHighResolutionCaptureEnabled = true 
     print("Camera output added to the camera session") 
    } else { 
     print("Could not add camera photo output to the camera session") 
     cameraSession.commitConfiguration() 
     return 
    } 

    cameraSession.commitConfiguration() 

    cameraSession.startRunning() 
} 

CaptureButton

@IBOutlet weak var cameraShutter: UIButton! 
@IBAction func cameraShutter(_ sender: UIButton) { 
    let photoSettings = AVCapturePhotoSettings() 
    photoSettings.flashMode = .on 
    photoSettings.isHighResolutionPhotoEnabled = true 
    photoSettings.isAutoStillImageStabilizationEnabled = true 
    if photoSettings.availablePreviewPhotoPixelFormatTypes.count > 0 { 
     photoSettings.previewPhotoFormat = [ kCVPixelBufferPixelFormatTypeKey as String : photoSettings.availablePreviewPhotoPixelFormatTypes.first!] 
    } 
    cameraPhotoOutput.capturePhoto(with: photoSettings, delegate: self) 
} 

的iOS观测相机功能

func capture(_ captureOutput: AVCapturePhotoOutput, didFinishProcessingPhotoSampleBuffer photoSampleBuffer: CMSampleBuffer?, previewPhotoSampleBuffer: CMSampleBuffer?, resolvedSettings: AVCaptureResolvedPhotoSettings, bracketSettings: AVCaptureBracketedStillImageSettings?, error: Error?) { 
    if let photoSampleBuffer = photoSampleBuffer { 
     photoData = AVCapturePhotoOutput.jpegPhotoDataRepresentation(forJPEGSampleBuffer: photoSampleBuffer, previewPhotoSampleBuffer: previewPhotoSampleBuffer) 
     let photoDataProvider = CGDataProvider(data: photoData as! CFData) 
     let cgImagePhotoRef = CGImage(jpegDataProviderSource: photoDataProvider!, decode: nil, shouldInterpolate: true, intent: .absoluteColorimetric) 
     let newPhoto = UIImage(cgImage: cgImagePhotoRef!, scale: 1.0, orientation: UIImageOrientation.right) 
     self.takePhotoPreview.image = newPhoto 
     self.takePhotoPreview.isHidden = false 
    } 
     else { 
     print("Error capturing photo: \(error)") 
     return 
    } 
} 

好了，所以这里的交易 - 我把一个断点cameraPhotoOutput.capturePhoto(with: photoSettings, delegate: self)并在步入线路收到以下错误消息：

错误消息

致命错误：意外地发现零而展开的可选值 [运行细节]致命错误：意外地发现零而展开的可选值

上面的代码是直接从苹果公司的示例文档“AVCam”沿着输入来自SO Q & As（link,link，和其他重复这些答案的其他人）。我的最终目标是捕捉图像，并立即将图像和用户推送到新的ViewController进行编辑/发布/保存;然而，我正在使用一个UIImageView来确认捕捉......这首先不起作用。

那么，这是怎么回事呢？这让我坚持了几天。

夫特3，XCODE 8

Answer 1

好的，理解了它。 El Tomato与问题儿童走在了正确的轨道上，但这不是正确的处方。我的createCamera()功能设置为private，这当然会使内容在其身体外不可见。所以当我调用正确的AVCapturePhotoOutput()时，调用capturePhoto()调用执行时抛出所描述错误的缓冲区源不存在。

因此，这意味着该行：

cameraPhotoOutput.capturePhoto(with: photoSettings, delegate: self)

是正确的，但它只是不正确的设置成执行。为了确认正确执行我...

• 改变了我的private let photoOutput = AVCapturePhotoOutput()不断
• 到private let cameraPhotoOutput = AVCapturePhotoOutput()
• ，称那是恒定的直接private func createCamera()

这立即执行完美的图像捕捉。

而且更换cameraPhotoOutput，一个AVCapturePhotoOutput()，具有cameraOutput，一个AVCapturePhotoOutput!，被尝试和简单地再现的错误。

如果您有兴趣：cgImage创建过程在func capture(_ : capture...函数中保持不变。在其范围内，我还确定了相机设备的位置，如果是前置相机，则更改图像的方向，并将主照片发送到ReviewViewController上的var photoContent: UIImage?变量。

希望我的心理错误帮助别人:-)

Answer 2

尝试改变

cameraPhotoOutput.capturePhoto(with: photoSettings, delegate: self) 

成

cameraOutput.capturePhoto(with: photoSettings, delegate: self as AVCapturePhotoCaptureDelegate)