如何使用AVfoundation（swift3）将照片放置在imageView上

Question

My code takes a photo and saves it into photo gallery using avfoundation. I just don't know where to request that the photo that is being saved to photo gallery be also transferred to the image view which is:

@IBOutlet var placeImage: UIImageView!.

Code:

import UIKit
import AVFoundation

class ViewController: UIViewController, AVCapturePhotoCaptureDelegate     {
    @IBOutlet var cameraDisplay: UIView!
    var captureSession : AVCaptureSession!
    var cameraOutput : AVCapturePhotoOutput!
    var previewLayer : AVCaptureVideoPreviewLayer!

    @IBOutlet var placeImage: UIImageView!

    var currentImageView: UIImageView?

    override func viewDidLoad() {
        super.viewDidLoad()
        captureSession = AVCaptureSession()
        captureSession.sessionPreset = AVCaptureSessionPresetPhoto
        cameraOutput = AVCapturePhotoOutput()

        let device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)

        if let input = try? AVCaptureDeviceInput(device: device) {
            if (captureSession.canAddInput(input)) {
                captureSession.addInput(input)
                if (captureSession.canAddOutput(cameraOutput)) {
                    captureSession.addOutput(cameraOutput)

                    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
                    previewLayer.frame = CGRect(x: 10, y: 10, width: 300, height: 300)

                    // cameraDisplay.transform = cameraDisplay.transform.rotated(by: CGFloat(M_PI_2))
                    cameraDisplay.transform = cameraDisplay.transform.inverted()

                    cameraDisplay.layer.addSublayer(previewLayer)
                    captureSession.startRunning()
                }
            }
        }
    }

    @IBAction func TakePhoto(_ sender: Any) {
        let settings = AVCapturePhotoSettings()
        let previewpixel = settings.availablePreviewPhotoPixelFormatTypes.first!
        let previewformat = [
            kCVPixelBufferPixelFormatTypeKey as String: previewpixel, kCVPixelBufferWidthKey as String: 160,
            kCVPixelBufferHeightKey as String : 160]

        settings.previewPhotoFormat = previewformat
        cameraOutput.capturePhoto(with: settings, delegate: self)
    }

    func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        } else {
            let ac = UIAlertController(title: "Image Saved!", message: "Your image has been saved to your photos.", preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK", style: .default))
            present(ac, animated: true)
        }
    }

    func capture(_ captureOutput: AVCapturePhotoOutput, didFinishProcessingPhotoSampleBuffer photoSampleBuffer: CMSampleBuffer?, previewPhotoSampleBuffer: CMSampleBuffer?, resolvedSettings: AVCaptureResolvedPhotoSettings, bracketSettings: AVCaptureBracketedStillImageSettings?, error: Error?) {
        if let sampleBuffer = photoSampleBuffer,
            let previewBuffer = previewPhotoSampleBuffer,
            let dataImage = AVCapturePhotoOutput.jpegPhotoDataRepresentation(forJPEGSampleBuffer: sampleBuffer, previewPhotoSampleBuffer: previewBuffer){
                let dataProvider = CGDataProvider(data: dataImage as CFData)
                let cgImageRef: CGImage! = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
                let imagea = UIImage(cgImage: cgImageRef, scale: 1.0, orientation: UIImageOrientation.down)

                UIImageWriteToSavedPhotosAlbum(imagea, self, #selector(self.image(_:didFinishSavingWithError:contextInfo:)), nil)
        }
    }

Answer 1

Simply use your didFinishSavingWithError method:

func image(_ image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: UnsafeRawPointer) {
    if let error = error {
        let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        present(ac, animated: true)
    } else {
        placeImage.image = image
    }
}