CODEWITHSUNDEEP
iosswift4key-value-observing
Duck
Duck

Reputation: 36003

How to KVO observing of whiteBalanceMode property of AVCaptureDevice?

Apple says the properties whiteBalanceMode and exposureMode of AVCaptureDevice are KVO observable.

This is my first time programming in Swift, after a decade working in Objective-C.

KVO appears to be way more complex in Swift.

I have tried this:

var kvoWhiteBalanceObserving : NSKeyValueObservation?
@objc var capDevice : AVCaptureDevice?

later on...

capDevice = captureDevice

self.kvoWhiteBalanceObserving = observe(\.capDevice.whiteBalanceMode, options: [.old, .new]) { object, change in
        print(object.whiteBalanceMode)
}

Xcode points to the \. saying:

Type of expression is ambiguous without more context

How to I KVO this in swift 4?

Upvotes: 0

Views: 405

Answers (1)

JIE WANG
JIE WANG

Reputation: 1934

observe like this:

self.kvoWhiteBalanceObserving = capDevice?.observe(\.whiteBalanceMode, options: [.old, .new]) { object, change in
    print(object.whiteBalanceMode)
}

Upvotes: 2

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