ios - AVFoundation 相机预览层与水平方向不匹配(Swift 4)

Question

我一直在从 Internet 和 stackoverflow 获取一些代码片段来让一个简单的相机应用程序正常工作。但是，我注意到如果我将手机翻转到侧面位置，我看到两个问题:

1) 的相机预览层只占用半个屏幕

2) 并且相机的方向似乎没有改变；它保持固定在垂直位置

我的约束似乎很好，如果我在水平位置查看各种模拟器的 UIimageView(相机的预览层)，UImage 会正确拉伸(stretch)。所以不确定为什么相机预览层只拉伸(stretch)到屏幕的一半。

(ImagePreview = 相机预览层)

至于方向问题，这好像是编码问题？我在 stackoverflow 上查找了一些帖子，但我没有看到 Swift 4 的任何内容。不确定这些是否是在 Swift 4 中执行此操作的简单方法。

iPhone AVFoundation camera orientation

这是我的相机应用程序中的一些代码:

import Foundation
import AVFoundation
import UIKit

class CameraSetup{

    var captureSession = AVCaptureSession()
    var frontCam : AVCaptureDevice?
    var backCam : AVCaptureDevice?
    var currentCam: AVCaptureDevice?

    var captureInput: AVCaptureDeviceInput?
    var captureOutput: AVCapturePhotoOutput?


    var cameraPreviewLayer: AVCaptureVideoPreviewLayer?

    func captureDevice()
    {
        let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .unspecified)
        for device in discoverySession.devices{
            if device.position == .front{
                frontCam = device
            }
            else if device.position == .back{
                backCam = device}

            do {
                try backCam?.lockForConfiguration()
                backCam?.focusMode = .autoFocus
                backCam?.exposureMode = .autoExpose
                backCam?.unlockForConfiguration()
            }
            catch let error{
                print(error)}
            }
        }



    func configureCaptureInput(){
        currentCam = backCam!
        do{
            captureInput = try AVCaptureDeviceInput(device: currentCam!)
            if captureSession.canAddInput(captureInput!){
                captureSession.addInput(captureInput!)
            }
        }
        catch let error{
            print(error)
        }
    }




func configureCaptureOutput(){
    captureOutput = AVCapturePhotoOutput()
    captureOutput!.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format: [AVVideoCodecKey : AVVideoCodecType.jpeg])], completionHandler: nil)
    if captureSession.canAddOutput(captureOutput!){
        captureSession.addOutput(captureOutput!)
    }
    captureSession.startRunning()
}

这是 PreviewLayer 函数:

    func configurePreviewLayer(view: UIView){
        cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        cameraPreviewLayer?.videoGravity = AVLayerVideoGravity.resize;
        cameraPreviewLayer?.zPosition = -1;
      view.layer.insertSublayer(cameraPreviewLayer!, at: 0)

        cameraPreviewLayer?.frame = view.bounds


    }

编辑:

按照建议，我将 view.bounds 行移到了上面一行:

func configurePreviewLayer(view: UIView){
        cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        cameraPreviewLayer?.videoGravity = AVLayerVideoGravity.resize;
        cameraPreviewLayer?.zPosition = -1;
        cameraPreviewLayer?.frame = view.bounds
        view.layer.insertSublayer(cameraPreviewLayer!, at: 0)

但是，问题依然存在:

这是水平 View :

Answer 1

我认为你应该使用 UIView 而不是 UIImageView.. 然后试试这个:

    cameraPreviewlayer?.videoGravity = AVLayerVideoGravityResize;
    cameraPreviewlayer?.zPosition = -1;
    cameraPreviewlayer?.frame = self.imagePreview.bounds