swift使用AVFoundation实现自定义相机

Posted 2021-09-05 hequnwang10

上一篇文章《swift使用AVFoundation实现自定义相机(一)》实现了使用swiftUI自定义相机，这一篇总结使用UIkit框架实现自定义相机。创建项目的时候选择这个。
代码ViewController.swift

//
//  ViewController.swift
//  Snapchat
//
//  Created by whq on 2021/8/13.
//
import AVFoundation
import UIKit

class ViewController: UIViewController {
    
    var session:AVCaptureSession?
    let output = AVCapturePhotoOutput()
    let previewLayer = AVCaptureVideoPreviewLayer()
    private let shutterButton:UIButton = {
        let button = UIButton(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
        button.layer.cornerRadius = 50
        button.layer.borderWidth = 10
        button.layer.borderColor = UIColor.white.cgColor
        return button
        
    }()
    

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .black
        previewLayer.backgroundColor = UIColor.systemRed.cgColor
        view.layer.addSublayer(previewLayer)
        view.addSubview(shutterButton)
        checkCameraPermissions()
        
        
        shutterButton.addTarget(self, action: #selector(didTapTakePhoto), for: .touchUpInside)
    }
    
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        previewLayer.frame = view.bounds
        
        shutterButton.center = CGPoint(x: view.frame.size.width/2,
                                       y: view.frame.size.height-100)
        
    }
    
    private func checkCameraPermissions(){
        switch AVCaptureDevice.authorizationStatus(for: .video) {
        case .notDetermined:
            AVCaptureDevice.requestAccess(for: .video){ [weak self] granted in
                guard granted else{
                    return
                }
                DispatchQueue.main.async {
                    self?.setUpCamera()
                }
            }
        case .restricted:
            break
        case .denied:
            break
        case .authorized:
            break
        @unknown default:
            break
        }
        
    }
    private func setUpCamera(){
        let session = AVCaptureSession()
        if let device = AVCaptureDevice.default(for: .video) {
            do{
                let input = try AVCaptureDeviceInput(device: device)
                
                if session.canAddInput(input) {
                    session.addInput(input)
                }
                if session.canAddOutput(output) {
                    session.addOutput(output)
                }
                previewLayer.videoGravity = .resizeAspectFill
                previewLayer.session = session
                session.startRunning()
                self.session = session
                
            }
            catch{
                print(error)
            }
        }
    }
    
    @objc private func didTapTakePhoto(){
        output.capturePhoto(with: AVCapturePhotoSettings(), delegate: self)
    }
}
extension ViewController:AVCapturePhotoCaptureDelegate{
    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        guard let data = photo.fileDataRepresentation() else {
            return
        }
        
        
        let image = UIImage(data: data)
        session?.stopRunning()
        
        let imageView = UIImageView(image: image)
        imageView.contentMode = .scaleAspectFill
        imageView.frame = view.bounds
        view.addSubview(imageView)
    }
}