Question

我有一些使用AVKit和AVCapturePhotoCaptureDelegate的Camera功能。

import UIKit 
import AVKit

class CaptureImageClass: NSObject, AVCapturePhotoCaptureDelegate {

    var photoData: Data?

    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {

        if let error = error {
            print("Error capturing photo: \(error)")
        } else {
            photoData = photo.fileDataRepresentation() //Cannot assign value of type 'Data?' to type 'Data?'
        }
    }

    func capture(_ output: AVCapturePhotoOutput, didFinishCaptureForResolvedSettings resolvedSettings: AVCaptureResolvedPhotoSettings, error: Error?) {
        guard let photoData = photoData else {
            print("No photo data resource")
            return
        }
        let capturedImage = UIImage.init(data: photoData , scale: 1.0) //Cannot convert value of type 'Data' to expected argument type 'Data'
        if let image = capturedImage {
            UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
        }
    }
}

当我创建独立项目时，此代码编译没有问题。但是当我尝试申请另一个项目时，它会出现诸如Cannot assign value of type 'Data?' to type 'Data?'和Cannot convert value of type 'Data' to expected argument type 'Data'之类的错误这个问题是由不同的Swift版本引起的吗？

注意：此“另一个项目”的部署目标是iOS 10和Swift 3，并且将func capture使用didFinishCaptureForResolvedSettings，而不能使用func photoOutput 我的独立项目正在使用Swift 4运行，并且部署目标是iOS 11.3

Answer 1

检查错误是否不是由设备的iOS版本引起的。

请记住

func photoOutput(_ output: AVCapturePhotoOutput, 
didFinishProcessingPhoto 
photo: AVCapturePhoto, 
error: Error?) {

适用于iOS11，适用于iOS10及更高版本，您应使用

optional func photoOutput(_ output: AVCapturePhotoOutput,
 didFinishProcessingPhoto photoSampleBuffer: CMSampleBuffer?,
previewPhoto previewPhotoSampleBuffer: CMSampleBuffer?,
resolvedSettings: AVCaptureResolvedPhotoSettings, 
bracketSettings: AVCaptureBracketedStillImageSettings?, 
error: Error?)

也

fileDataRepresentation()

可用于iOS11和更高版本

希望有帮助...

Answer 2

某人已覆盖cir['date'] = ['3-15','4-15', '1-16', '2-16', '3-16', '4-16', '1-17', '2- 17', '3-17', '4-17'] cir['value'] = [78.4, 13.5, 19.8, 19, 78.4, 123.2, 82.6, 86.4, 83.5, 12.2.4] cir.plot.bar()类型。您可以使用：

Data

Answer 3

通过使用解决 func capture（_ captureOutput：AVCapturePhotoOutput， didFinishProcessingPhotoSampleBuffer photoSampleBuffer：CMSampleBuffer ?, PreviewPhotoSampleBuffer：CMSampleBuffer ?， resolveSettings：AVCaptureResolvedPhotoSettings， bracketSettings：AVCaptureBracketedStillImageSettings ?，错误：错误？）{

    // Make sure we get some photo sample buffer
    guard error == nil,
        let photoSampleBuffer = photoSampleBuffer else {
            print("Error capturing photo: \(String(describing: error))")
            return
    }
    // Convert photo same buffer to a jpeg image data by using // AVCapturePhotoOutput
    guard let imageData =
        AVCapturePhotoOutput.jpegPhotoDataRepresentation(forJPEGSampleBuffer: photoSampleBuffer, previewPhotoSampleBuffer: previewPhotoSampleBuffer) else {
            return
    }

    let dataProvider = CGDataProvider(data: imageData as CFData)

    let cgImageRef = CGImage(jpegDataProviderSource: dataProvider!, decode: nil, shouldInterpolate: true, intent: CGColorRenderingIntent.absoluteColorimetric)


    let image = UIImage(cgImage: cgImageRef!, scale: 1.0, orientation: UIImageOrientation.right)

    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}

Swift：将“数据”类型的值错误地转换为“数据”类型

3 个答案: