Question

我想用AVCaptureVideoPreviewLayer作为子图层旋转UIVIew。

在UIView中出现两个按钮（一个将视频预览图层向左旋转，另一个向右旋转），当用户点击其中一个按钮时，每次都会将预览图层旋转1度。

override func viewDidLoad() {
   ...
   videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
   videoPreviewLayer?.frame = self.view.bounds
   videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
   previewView.layer.addSublayer(videoPreviewLayer!)
}


@objc func rotateRight() {
    degrees += 1

    // 1st possibility - Scale the UIView that contains the previewLayer for 2x
    /*
    previewView.transform = CGAffineTransform(scaleX: 2, y: 2)
    previewView.transform = CGAffineTransform(rotationAngle: (CGFloat(degrees / 180.0 * .pi)))
    previewView.transform = CGAffineTransform.identity
    */

    // 2nd possibility - Make bigger the previewLayer so when it's rotate doesn't appear the background color of the UIView
    /*
    videoPreviewLayer?.frame = CGRect(x: -200, y: -200, width: 800, height: 1200)
    videoPreviewLayer?.position = CGPoint(x: view.bounds.midX, y: view.bounds.midY)
    videoPreviewLayer?.transform = CATransform3DMakeRotation(CGFloat(degrees / 180.0 * .pi), 0.0, 0.0, 1.0)
    */

    // 3rd possibility
    /*
    videoPreviewLayer?.frame = CGRect(x: -200, y: -200, width: 800, height: 1200)
    videoPreviewLayer?.position = CGPoint(x: view.bounds.width * 0.5, y: view.bounds.width * 0.5)
    videoPreviewLayer?.transform = CATransform3DMakeRotation(CGFloat(degrees / 180.0 * .pi), 0.0, 0.0, 1.0)
    */

    // 4th possibility
    UIView.animate(withDuration: 1, animations: {
        self.previewView.contentMode = UIViewContentMode.scaleToFill
        self.previewView.transform = CGAffineTransform(rotationAngle: CGFloat(self.degrees))
    })
}

需要最终结果 Final result required

实际结果

我尝试了4种不同的方法来创建这种旋转，但所有这些都失败了。我希望所有这些代码及其结果不会让你更加困惑。

第二个可能性代码的结果 link

第3种可能性代码的结果 link

Answer 1

你试过吗

if let videoPreviewLayerConnection = videoPreviewLayer.connection {
    videoPreviewLayerConnection.videoOrientation = desiredOrientation
}

使用AVCaptureVideoPreviewLayer作为子图层旋转UIView

1 个答案: