如何在iOS8.1上使用Swift按序列拍摄多张照片(每张照片延迟1秒)？

Question

我试图在单个用户点击相机预览后拍几张照片,这样我就可以呈现它们,用户可以选择一个时机最好或者在"电影条"模式下全部使用.预期的用户体验是:"我打开相机,拍照,然后我看到每秒拍摄5张照片.我没有按下'拍照'按钮5次,一个就足以启动序列" .

我是iOS和Swift的新手,我的工作基于'Swift Recipes'一书(https://www.safaribooksonline.com/library/view/ios-8-swift/9781491908969/).

拍摄单张照片的源代码是:

controller = UIImagePickerController()
    if let theController = controller{
        theController.sourceType = .Camera
        theController.mediaTypes = [kUTTypeImage as NSString]
        theController.allowsEditing = true
        theController.delegate = self
        presentViewController(theController, animated: true, completion: nil)
    }

加上相关的图像处理(通过func imagePickerController).我尝试使用上面的控制器目标,但悲惨地失败了:(我相信这不是正确的方式来获得我想要的,但我很难找到合适的.任何帮助将不胜感激.

Answer 1

我不知道是否有这种行为的模式UIImagePickerController.如果我是你,我会使用AVFoundation来实现这一点.

import UIKit
import AVFoundation

class ViewController: UIViewController {

    var connection: AVCaptureConnection!
    var output: AVCaptureStillImageOutput!
    var videoPreviewLayer: AVCaptureVideoPreviewLayer!
    @IBOutlet var videPreviewView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.createCamera()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        self.videoPreviewLayer.bounds = self.videPreviewView.bounds
        self.videoPreviewLayer.position = CGPoint(x: CGRectGetMidX(self.videPreviewView.bounds), y: CGRectGetMidY(self.videPreviewView.bounds))
    }

    func createCamera() {
        let captureSession = AVCaptureSession()

        if captureSession.canSetSessionPreset(AVCaptureSessionPresetHigh) {
            captureSession.sessionPreset = AVCaptureSessionPresetHigh
        } else {
            println("Error: Couldn't set preset = \(AVCaptureSessionPresetHigh)")
            return
        }

        let cameraDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)

        var error: NSError?
        let inputDevice = AVCaptureDeviceInput.deviceInputWithDevice(cameraDevice, error: &error) as AVCaptureDeviceInput
        if let error = error {
            println("Error: \(error)")
            return
        }

        if captureSession.canAddInput(inputDevice) {
            captureSession.addInput(inputDevice)
        } else {
            println("Error: Couldn't add input device")
            return
        }

        let imageOutput = AVCaptureStillImageOutput()
        if captureSession.canAddOutput(imageOutput) {
            captureSession.addOutput(imageOutput)
        } else {
            println("Error: Couldn't add output")
            return
        }

        // Store imageOutput. We will need it to take photo
        self.output = imageOutput

        let connection = imageOutput.connections.first as AVCaptureConnection!
        // Store this connection in property. We will need it when we take image.
        self.connection = connection
        connection.videoOrientation = AVCaptureVideoOrientation.Portrait

        captureSession.startRunning()

        // This will preview the camera
        let videoLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        videoLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
        videoLayer.contentsScale = UIScreen.mainScreen().scale

        self.videPreviewView.layer.addSublayer(videoLayer)

        // Store this layer instance in property. We will place it into a view
        self.videoPreviewLayer = videoLayer
    }

    func takePhoto(completion: (UIImage?, NSError?) -> Void) {
        self.output.captureStillImageAsynchronouslyFromConnection(self.connection) { buffer, error in
            if let error = error {
                completion(nil, error)
            } else {
                let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
                let image = UIImage(data: imageData, scale: UIScreen.mainScreen().scale)
                completion(image, nil)
            }
        }
    }
}

现在你所要做的就是创建一个调用takePhoto3次的动作.你可以NSTimer用来做这件事.