Question

这是在iPad Mini上显示时的视图。在iPhone上，相机图像看起来是正确的，它填满了屏幕。如何告诉相机填满整个区域？我的代码跟随图像。

事实上，该项目在较小的设备上运行正常，只有当我移动到iPad时它才能显示这个边界。也许在iPhone 7上，但我没有。在模拟器上运行没有任何区别，因为它是受限制的摄像机视图。我已经包含了所有代码，因为它与它密切相关。

import UIKit
import AVFoundation
import Foundation

class ViewController: UIViewController {

@IBOutlet weak var navigationBar: UINavigationBar!
@IBOutlet weak var imgOverlay: UIImageView!
@IBOutlet weak var btnCapture: UIButton!

@IBOutlet weak var shapeLayer: UIView!

let captureSession = AVCaptureSession()
let stillImageOutput = AVCaptureStillImageOutput()
var previewLayer : AVCaptureVideoPreviewLayer?

//=====================
let screenWidth = UIScreen.main.bounds.size.width
let screenHeight = UIScreen.main.bounds.size.height
var aspectRatio: CGFloat = 1.0


var viewFinderHeight: CGFloat = 0.0
var viewFinderWidth: CGFloat = 0.0
var viewFinderMarginLeft: CGFloat = 0.0
var viewFinderMarginTop: CGFloat = 0.0
//======================


// If we find a device we'll store it here for later use
var captureDevice : AVCaptureDevice?

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    //On iPad Mini this returns 760 x 1024 = correct
    //On the iPhone SE, this returns 320x568 = correct
    print("Width: \(screenWidth)")
    print("Height: \(screenHeight)")

    //=======================

    captureSession.sessionPreset = AVCaptureSessionPresetHigh

    if #available(iOS 10.0, *) {
        if let devices = AVCaptureDevice.defaultDevice(withDeviceType: .builtInWideAngleCamera, mediaType: AVMediaTypeVideo, position: .back) {

            print("Device name: \(devices.localizedName)")

        }
    } else {
        // Fallback on earlier versions
    }

    if let devices = AVCaptureDevice.devices() as? [AVCaptureDevice] {
        // Loop through all the capture devices on this phone
        for device in devices {

            print("Device name: \(device.localizedName)")

            // Make sure this particular device supports video
            if (device.hasMediaType(AVMediaTypeVideo)) {
                // Finally check the position and confirm we've got the back camera
                if(device.position == AVCaptureDevicePosition.back) {
                    captureDevice = device
                    if captureDevice != nil {
                        print("Capture device found")
                        beginSession()
                    }
                }
            }
        }
    }
}


@IBAction func actionCameraCapture(_ sender: AnyObject) {

    print("Camera button pressed")
    saveToCamera()
}

func beginSession() {

    do {
        try captureSession.addInput(AVCaptureDeviceInput(device: captureDevice))
        stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]

        if captureSession.canAddOutput(stillImageOutput) {
            captureSession.addOutput(stillImageOutput)
        }

    }
    catch {
        print("error: \(error.localizedDescription)")
    }

    guard let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) else {
        print("no preview layer")
        return
    }
    // this is what displays the camera view. But - it's on TOP of the drawn view, and under the overview. ??
    //=======================================
    self.view.layer.addSublayer(previewLayer)
    previewLayer.frame = self.view.layer.frame
    //self.previewLayer?.frame = self.view.bounds
    //=======================================


    imgOverlay.frame = self.view.frame
    imgOverlay.image = self.drawCirclesOnImage(fromImage: nil, targetSize: imgOverlay.bounds.size)

    self.view.bringSubview(toFront: navigationBar)
    self.view.bringSubview(toFront: imgOverlay)
    self.view.bringSubview(toFront: btnCapture)
    // don't use shapeLayer anymore...
    //      self.view.bringSubview(toFront: shapeLayer)


    captureSession.startRunning()
    print("Capture session running")

}


func getImageWithColor(color: UIColor, size: CGSize) -> UIImage {
    let rect = CGRect(origin: CGPoint(x: 0, y: 0), size: CGSize(width: size.width, height: size.height))
    UIGraphicsBeginImageContextWithOptions(size, false, 0)
    color.setFill()
    UIRectFill(rect)
    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return image
}

func drawCirclesOnImage(fromImage: UIImage? = nil, targetSize: CGSize? = CGSize.zero) -> UIImage? {

    if fromImage == nil && targetSize == CGSize.zero {
        return nil
    }

    var tmpimg: UIImage?

    if targetSize == CGSize.zero {

        tmpimg = fromImage

    } else {

        tmpimg = getImageWithColor(color: UIColor.clear, size: targetSize!)

    }

    guard let img = tmpimg else {
        return nil
    }

    let imageSize = img.size
    let scale: CGFloat = 0
    UIGraphicsBeginImageContextWithOptions(imageSize, false, scale)

    img.draw(at: CGPoint.zero)

    let w = imageSize.width

    //print("Width: \(w)")

    let midX = imageSize.width / 2
    let midY = imageSize.height / 2

    // red circles - radius in %
    let circleRads = [ 0.07, 0.13, 0.17, 0.22, 0.29, 0.36, 0.40, 0.48, 0.60, 0.75 ]

    // center "dot" - radius is 1.5%
    var circlePath = UIBezierPath(arcCenter: CGPoint(x: midX,y: midY), radius: CGFloat(w * 0.015), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)

    UIColor.red.setFill()
    circlePath.stroke()
    circlePath.fill()

    // blue circle is between first and second red circles
    circlePath = UIBezierPath(arcCenter: CGPoint(x: midX,y: midY), radius: w * CGFloat((circleRads[0] + circleRads[1]) / 2.0), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)

    UIColor.blue.setStroke()
    circlePath.lineWidth = 2.5
    circlePath.stroke()

    UIColor.red.setStroke()

    for pct in circleRads {

        let rad = w * CGFloat(pct)

        circlePath = UIBezierPath(arcCenter: CGPoint(x: midX, y: midY), radius: CGFloat(rad), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)

        circlePath.lineWidth = 2.5
        circlePath.stroke()

    }

    let newImage = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    return newImage
}

func saveToCamera() {

    if let videoConnection = stillImageOutput.connection(withMediaType: AVMediaTypeVideo) {
        stillImageOutput.captureStillImageAsynchronously(from: videoConnection, completionHandler: { (CMSampleBuffer, Error) in

            if let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(CMSampleBuffer) {
                if let cameraImage = UIImage(data: imageData) {

                    if let nImage = self.drawCirclesOnImage(fromImage: cameraImage, targetSize: CGSize.zero) {
                        UIImageWriteToSavedPhotosAlbum(nImage, nil, nil, nil)
                    }

                }
            }
        })
    }
}



override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

Answer 1

试试这个，它与我的application一起工作正常。 :)

 override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
            super.viewWillTransition(to: size, with: coordinator)
            // Update camera orientation
            let videoOrientation: AVCaptureVideoOrientation
            switch UIDevice.current.orientation {
            case .portrait:
                videoOrientation = .portrait
            case .portraitUpsideDown:
                videoOrientation = .portraitUpsideDown
            case .landscapeLeft:
                videoOrientation = .landscapeRight
            case .landscapeRight:
                videoOrientation = .landscapeLeft
            default:
                videoOrientation = .portrait
            }
            cameraView.layer.connection.videoOrientation = videoOrientation
        }

Answer 2

我找到了答案。 iPhone SE和iPad Mini上的视频预览图像现在尺寸合适。现在也应该对其他人正确。

将原始ViewController.swift中的代码（从第107行结束第127行开始）更改为此代码。为了清楚起见，我已将注释掉的部分留在原处。

关键是 previewLayer？.videoGravity = AVLayerVideoGravityResizeAspectFill;

感谢别人的帮助。

         //==============================
    /*
    guard let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) else {
        print("no preview layer")
        return
    }
    */
    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession);
    previewLayer?.frame = view.layer.bounds
    previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill;
    view.layer.addSublayer(previewLayer!);


    // this is what displays the camera view.
    //=======================================
    self.view.layer.addSublayer(previewLayer!)
    previewLayer?.frame = self.view.layer.bounds
    //self.previewLayer?.frame = self.view.bounds


    //=======================================

如何在预览图层上设置正确的相机图像尺寸？

2 个答案: