How to convert code AVFoundation objective c to Sw

问题:

I am using AVFoundation in swift for take pictures but I can't convert any func lines of code from objective c to Swift. My func code is:

 - (void) capImage { //method to capture image from AVCaptureSession video feed
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in stillImageOutput.connections) {

    for (AVCaptureInputPort *port in [connection inputPorts]) {

        if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
            videoConnection = connection;
            break;
        }
    }

    if (videoConnection) {
        break;
    }
}

NSLog(@"about to request a capture from: %@", stillImageOutput);
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {

    if (imageSampleBuffer != NULL) {
        NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
        [self processImage:[UIImage imageWithData:imageData]];
    }
}];

}

This line send me error AnyObject[]does not conform to protocol sequencfe..:

 for (AVCaptureInputPort *port in [connection inputPorts]) {

In swift:

  for port:AnyObject in connection.inputPorts {

And I don't know how convert this line:

 [stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {

Can u help me to convert to swift? Thanks!!

回答1:

for (AVCaptureInputPort *port in [connection inputPorts]) { )

Arrays of AnyObject should be cast to arrays of your actual type before interating, like this:

for (port in connection.inputPorts as AVCaptureInputPort[]) { }

In terms of blocks to closures, you just have to get the syntax correct.

stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection) {
    (imageSampleBuffer, error) in // This line defines names the inputs
    //...
}

Note that this also uses Trailing Closure Syntax. Do read up on the docs more!

EDIT: In terms of initializers, they now look like this:

let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageSampleBuffer)
self.processImage(UIImage(data:imageData))

回答2:

Try this

    var videoConnection :AVCaptureConnection?
   if let videoConnection = self.stillImageOutput.connectionWithMediaType(AVMediaTypeVideo){
     self.stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: { (buffer:CMSampleBuffer!, error: NSError!) -> Void in
     if let exifAttachments = CMGetAttachment(buffer, kCGImagePropertyExifDictionary, nil) {
         let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
         self.previewImage.image = UIImage(data: imageData)
         UIImageWriteToSavedPhotosAlbum(self.previewImage.image, nil, nil, nil)
      }
     })
   }

回答3:

This should answer the problem with the ports:

if let videoConnection = stillImageOuput.connectionWithMediaType(AVMediaTypeVideo){//take a photo here}