ios - 错误: 'Call can throw but is not marked with try and error not handled'

Question

我收到了上述错误，并尝试通过添加do/catch块来对此进行修改。由于某种原因，错误不会消失。有谁知道为什么会这样？

 override func viewDidAppear(animated: Bool) {
    super.viewWillAppear(animated)

    captureSession = AVCaptureSession()
    captureSession?.sessionPreset = AVCaptureSessionPreset1920x1080

    let backCamera = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)

    do {

        let input = AVCaptureDeviceInput(device: backCamera)

        captureSession?.addInput(input)

        stillImageOutput = AVCaptureStillImageOutput()
        stillImageOutput?.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]

        if (captureSession?.canAddOutput(stillImageOutput) != nil){
            captureSession?.addOutput(stillImageOutput)

            previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
            previewLayer?.videoGravity = AVLayerVideoGravityResizeAspect
            previewLayer?.connection.videoOrientation = AVCaptureVideoOrientation.Portrait
            oview.layer.addSublayer(previewLayer!)
            captureSession?.startRunning()

        }

    } catch {

    }

}

Answer 1

提示在错误描述中:Error: 'Call can throw but is not marked with try and error not handled'
您尚未用try标记可能引发的 call

我没有在其中抛出的调用，而是找到了一个并在其前面放置try的调用。如果您要分配一个值，请尝试在=的右侧进行操作

编辑

只是看了看文档，看起来像是你的

let input = AVCaptureDeviceInput(device: backCamera)

可以抛出的声明。像这样在 =之后尝试一下

let input = try AVCaptureDeviceInput(device: backCamera)

然后，您可以在 print(error)中使用 catch来查看任何潜在错误