Barcode on swift 4

I figured it out but Apple didn't make it so obvious. The callback function from the delegate AVCaptureMetadataOutputObjectsDelegate has been renamed and the parameter names are different!

So, replace

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!)

to

func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection)

My view controller is now scanning QR Codes as before after this. It has the same parameters but the first parameter name is different. Change the function and parameter names and build/run.

Hope this helps!

After changing the delegate call back :

From

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!)

To

func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection)

I need to set all available types for metadataObjectTypes too as below-

output.metadataObjectTypes=output.availableMetadataObjectTypes

After changing your code from:

func metadataOutput(captureOutput: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {}

to:

func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {}

everything works again.