捏合手势放大和缩小相机 swift

Question

我在我的应用程序中使用前置摄像头。我希望用户在拍照时可以放大和缩小相机

我试过这个代码

let device = AVCaptureDevice.default(for: .video)
print(sender.scale)
let vZoomFactor = sender.scale * prevZoomFactor
if sender.state == .ended {
    prevZoomFactor = vZoomFactor >= 1 ? vZoomFactor : 1
}

if sender.state == .changed{
    do {
        try device!.lockForConfiguration()
        if (vZoomFactor <= device!.activeFormat.videoMaxZoomFactor) {
            device!.videoZoomFactor = max(1.0, min(vZoomFactor, device!.activeFormat.videoMaxZoomFactor))
            device?.unlockForConfiguration()
        } else {
            print("Unable to set videoZoom: (max \(device!.activeFormat.videoMaxZoomFactor), asked \(vZoomFactor))")
        }
    } catch {
        print("\(error.localizedDescription)")
    }
}

后置摄像头一切正常，但前置摄像头不适用于变焦。

Answer 1

嗯，在这段代码上花了几个小时后，我找到了我犯错的地方。

let device = AVCaptureDevice.default(for: .video)

默认情况下，这将获得后置摄像头并完美运行，但当我将其切换到前置时，它一直被视为后置摄像头，所以我只是添加了一个条件

    if  currentcam == frontcam {
      let device = frontcam
      //did other stuff for zooimng
     } 

   else {
     let device = AVCaptureDevice.default(for: .video)
     //did other stuff for zooimng
  }

这对我来说效果很好

捏合手势放大和缩小相机 swift

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