Swift 개발 팁

커스텀 클래스 객체 파일 입출력

기본이 되는 중요한 기능 중에 하나인데 이렇게 쓸만한 레퍼런스가 없음에 놀랍다.

// Save object in document directory
    func saveObject(fileName: String, object: Any) -> Bool {
        
        let filePath = self.getDirectoryPath().appendingPathComponent(fileName)//1
        do {
            let data = try NSKeyedArchiver.archivedData(withRootObject: object, requiringSecureCoding: false)//2
            try data.write(to: filePath)//3
            return true
        } catch {
            print("error is: \(error.localizedDescription)")//4
        }        
        return false
    }
    
    // Get object from document directory
    func getObject(fileName: String) -> Any? {
        
        let filePath = self.getDirectoryPath().appendingPathComponent(fileName)//5
        do {
            let data = try Data(contentsOf: filePath)//6
            let object = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data)//7
            return object//8
        } catch {
            print("error is: \(error.localizedDescription)")//9
        }
        return nil
    }
    
    //Get the document directory path
    //10
    func getDirectoryPath() -> URL {
        let arrayPaths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        return arrayPaths[0]
    }

class Car: NSObject, NSCoding {
    
    var brand: String?
    var madel: String?
    
    func encode(with aCoder: NSCoder) {
        aCoder.encode(self.madel, forKey:"madel")
        aCoder.encode(self.brand, forKey:"brand")
    }
    
    required init?(coder aDecoder: NSCoder) {
        self.madel = aDecoder.decodeObject(forKey:"madel") as? String
        self.brand = aDecoder.decodeObject(forKey:"brand") as? String
    }
    
    init(barand: String, model: String) {
        self.brand = barand
        self.madel = model
    }
}

let car = Car(barand: "Audi", model: "A4")
if self.saveObject(fileName: "myCar", object: car) {
    print("saved")
} else {
    print("not saved")
}

// Get the saved Car object
if let car = self.getObject(fileName: "myCar") as? Car {
    print("my car is: \(car)")
}

https://www.swiftdevcenter.com/save-and-get-objects-using-nskeyedarchiver-and-nskeyedunarchiver-swift-5/

Swift Development Center NSKeyedArchiver and NSKeyedUnarchive

https://medium.com/@CoreyWDavis/reading-writing-and-deleting-files-in-swift-197e886416b0

Reading, Writing, and Deleting Files in Swift

 

비동기 처리를 위한 OperationQueue

안드로이드의 AsyncTask 처럼 무거운 작업을 쓰레드로 돌리면서 메인 쓰레드는 그대로 동작하도록 구현할 때 필요하다

OperationQueue().addOperation {
            OperationQueue.main.addOperation {
            	//UI 작업
            }
            
            //백그라운드 작업
}

https://etst.tistory.com/114

[ iOS 앱 개발 - Swift] 비동기 프로그래밍과 OperationQueue

 

배경이 투명한 ViewController 실행

func presentModal() {
    let modalController = ModalViewController()
    modalViewController.modalPresentationStyle = .overCurrentContext
    present(modalViewController, animated: true, completion: nil)
}

override func viewDidLoad() {
    super.viewDidLoad()

    view.isOpaque = false
    view.backgroundColor = .clear // try other colors, say: .white or black with Alpha etc.
}

https://www.it-swarm.dev/ko/swift/%eb%aa%a8%eb%8b%ac-%ed%91%9c%ec%8b%9c-%eb%b7%b0-%ec%bb%a8%ed%8a%b8%eb%a1%a4%eb%9f%ac%ec%9d%98-%ed%88%ac%eb%aa%85%ed%95%9c-%eb%b0%b0%ea%b2%bd/1049818603/

swift — 모달 표시 뷰 컨트롤러의 투명한 배경

 

효과음 재생하기

import AudioToolbox

func playSound(filename:String, ext:String) {
        if let soundUrl = Bundle.main.url(forResource: filename, withExtension: ext) {
            var soundId:SystemSoundID = 0
            AudioServicesCreateSystemSoundID(soundUrl as CFURL, &soundId)
            
            AudioServicesAddSystemSoundCompletion(soundId, nil, nil, { (soundId, clientData) -> Void in
                AudioServicesDisposeSystemSoundID(soundId)
            }, nil)
            AudioServicesPlaySystemSound(soundId)
        }
    }

https://robatokim.tistory.com/entry/SWIFT-AudioServicesPlaySystemSound%EC%9C%BC%EB%A1%9C-%ED%9A%A8%EA%B3%BC%EC%9D%8C-%EC%9E%AC%EC%83%9D%ED%95%98%EA%B8%B0

[SWIFT] AudioServicesPlaySystemSound으로 효과음 재생하기

 

다중 배열 사용

이 부분은 기대보다 사용이 불편하다.

// this is our array of arrays
var groups = [[String]]()

// we create three simple string arrays for testing
var groupA = ["England", "Ireland", "Scotland", "Wales"]
var groupB = ["Canada", "Mexico", "United States"]
var groupC = ["China", "Japan", "South Korea"]

// then add them all to the "groups" array
groups.append(groupA)
groups.append(groupB)
groups.append(groupC)

// this will print out the array of arays
print("The groups are:", groups)

// we now append an item to one of the arrays
groups[1].append("Costa Rica")
print("\nAfter adding Costa Rica, the groups are:", groups)

// and now print out groupB's contents again
print("\nGroup B still contains:", groupB)

https://www.hackingwithswift.com/example-code/arrays/how-do-you-create-multi-dimensional-arrays

How do you create multi-dimensional arrays? - free Swift 5.1 example code and tips

 

ListItemViewCell에서 delegation 처리 

매번 까먹어서 쓸때마다 찾아봐야하는... 

protocol CustomCellDelegate: class {
    func animationStarted()
    func animationFinished()
}

class CustomCell: UITableViewCell {
    // Don't unwrap in case the cell is enqueued!
    weak var delegate: CustomCellDelegate?

    /* Some initialization of the cell */

    func performAnimation() {
        delegate?.animationStarted()
        UIView.animate(withDuration: 0.5, animations: {
            /* Do some cool animation */
        }) { finished in
            self.delegate?.animationFinished()
        }
    }
}

https://stackoverflow.com/questions/47079135/delegate-method-to-uitableviewcell-swift

Delegate Method to UItableViewCell Swift