邁向一萬小時成長之路: swift程式碼小碎片筆記

//判斷是否為nil
//let image = UIImage(named: "foo")
if let image = UIImage(named: "foo") {
//TODO: image != nil
} else {
//TODO: image == nil
}

//用","將Array組成字串
let commaSeparatedArrayElements: String = ",".join(myArray)

//casting:用"as"來達成強轉型
var destinationViewController: Anyobject
let calcVC = destinationViewController as CalculatorViewController
//為了避免程式crash
if let calcVC = destinationViewController as? CalculatorViewController { ... }
//也可以用is來判斷型別
if destinationViewController is CalculatorViewController { ... }
//用括號強轉型
let button: AnyObject = UIButton.buttonWithType( UIButtonType.System)
let title = (button as UIButton).currentTitle

//取得substring
var s = "hello"
let index = advance(s.startIndex, 2) //取得"l"的index
s.splice("abc", index) //"heabcllo"
let startIndex = advance(s.startIndex, 1)
let endIndex = advance(s.startIndex, 6)
let substring = s[index..<endIndex] //"eabcl"

//雙問號代表"如果a不等於nil則，value = a，如果a為nil，則value = b"
let value = a ?? b 中的 a??b 代表 a != nil ? a! : b

//PropertyList就是plist，是定義為一個AnyObject的容器，這個容器只用來存放下列之中某一種(而且只能一種)Class：NSString、NSArray、NSDictionary、NSNumber、NSData、NSDate。

//String與NSString，Array與NSArray，Dictionary與NSDictionary可以直接casing所以as後面不用加問號
let string1 = "haha"
let string2:NSString = string1 as NSString

//Optional只是一種enum，在swift中沒有objective-C那種萬物皆空的nil(空指標)，swift裡的nil也是一個值，但物值只要宣告出來就會指給它一個Optional<T>.None值，所以也可以直接判斷是否等於nil。

Conceptually it is like this (the <T> is a generic like as in Array<T>) ...

enum Optional<T> {

case None
case Some(T)

}

let x: String? = nil
... is ...

let x = Optional<String>.None

let x: String? = “hello”
... is ...

let x = Optional<String>.Some(“hello”)

var y = x!

... is ...

switch x {

case Some(let value): y = value
case None: // raise an exception

}

//UIView的初始化有下列兩種，如果要用的話，請兩個都implement

init(frame: CGRect) // initializer if the UIView is created in code

init(coder: NSCoder) // initializer if the UIView comes out of a storyboard

//這不是init方法，它只有在透過storyboard或nib去呼叫UIView時會被觸發，觸發的時機是在init(coder: NSCoder)之後，立刻執行

awakeFromNib

//在view座標系中，都要使用CGFloat
let cgf = CGFloat(aDoubleValue)

//view座標系

原點在左上角
單位是用point不是pixel

如果你想知道當下的device中一個point等於幾個pixel，你可以呼叫UIView的var contentScaleFactor: CGPoint來查看(目前大部份是2)

在view中繪圖(draw)的邊界

var bounds: CGPoint //這個view之內的座標系

這個UIView的位置

var center: CGPoint //這個view的中心點在superview中的座標
var frame: CGRect //這個view在superview中的origin與size

//Never call drawRect!!
因為UIView會跟很多其他的view有關聯，所以在drawRect之前系統要先處理這些交互作用。

用下列的func代替，iOS會處理完這些事之後，再幫你呼叫drawRect()

setNeedsDisplay()

setNeedsDisplayInRect(regionThatNeedsToBeRedrawn: CGRect)

//swift字串截取
var string="1234567890" let index = advance(string.startIndex, 5) let index2 = advance(string.endIndex, -6); var range = Range<String.Index>(start: index2,end: index) var s1:String=string.substringFromIndex(index) var s2:String=string.substringToIndex(index2) var s3=string.substringWithRange(range) println(s1)//67890 println(s2)//1234 println(s3)//5

//closure
//在class中宣告為property
var didLinkTapped: ((chatroomName: String!) -> Void)?
//在要執行的時機點呼叫

self.didLinkTapped!(chatroomName: chatroomName)

//在你對外的方法中傳入實做的部份

init(id: String, text: String, didLinkTapped: ((chatroomName: String!) -> Void)?) {

        super.init(id: id)

        self.didLinkTapped = didLinkTapped

}

//dispatch_after in swift

let delayTime = dispatch_time(DISPATCH_TIME_NOW,

            Int64(sec * Double(NSEC_PER_SEC)))

        dispatch_after(delayTime, dispatch_get_main_queue()) { () -> Void in

            self.removeFromSuperview()

        } //sec要設為double

//enum轉數字

yourEnum.rawValue

//加入一個AlertView，按下任何地方即離開

let alertController = UIAlertController(

            title: NSLocalizedString("Error", comment: "Error"),

            message: error?.localizedDescription,

            preferredStyle: .Alert)

        let closeAction = UIAlertAction(title: NSLocalizedString("CLOSE", comment: "Close"), style: .Cancel) {

            (action) in

            alertController.dismissViewControllerAnimated(true, completion: nil)

}

        alertController.addAction(closeAction)

        self.presentViewController(alertController, animated: true) {

            alertController.view.userInteractionEnabled = true

            if let window = alertController.view.window {

                var tapGestureRecognizer: UITapGestureRecognizer?

                tapGestureRecognizer = window.tapped() {

                    (sender: UITapGestureRecognizer) -> Void in

                    if sender.state == UIGestureRecognizerState.Ended {

                        let location: CGPoint = sender.locationInView(alertController.view)

                        // check tap point in alert window

                        if alertController.view.pointInside(location, withEvent: nil) == false {

                            alertController.dismissViewControllerAnimated(true, completion: nil)

}

}

                    window.removeGestureRecognizer(tapGestureRecognizer!)

}

                tapGestureRecognizer?.cancelsTouchesInView = false

}

}

//UIImageView rotation extension

import Foundation

extension UIImageView {

    func rotate360WithDuration(duration: Double, repeatCount: Float) {

        var fullRotation: CABasicAnimation = CABasicAnimation(keyPath: "transform.rotation")

        fullRotation.fromValue = 0

        fullRotation.toValue = ((360 * M_PI) / 180)

        fullRotation.duration = duration

        fullRotation.speed = 2.0

        if repeatCount == 0 {

            fullRotation.repeatCount = MAXFLOAT

        } else {

            fullRotation.repeatCount = repeatCount

}

        self.layer.addAnimation(fullRotation, forKey: "360")

}

    func stopAnimation() {

        self.layer.removeAllAnimations()

}

}

//更換UIBarButtonItem

let loadingImageView = UIImageView(image: UIImage(named: "IOS_loading_static") )

loadingImageView.rotate360WithDuration(2.0, repeatCount: 0)

let barButton = UIBarButtonItem(customView: loadingImageView)

self.navigationItem.rightBarButtonItem = barButton

//NSUserDefault

let defaults = NSUserDefaults.standardUserDefaults()

//read

let plist: AnyObject = defaults.objectForKey(String)

//write

defaults.setObject(AnyObject, forKey: String)

//大部份會自動儲存，但你可以用這個判斷來處理少部份的情況

if !defaults.synchronize() { /*TODO:error handling*/}

//在enum中使用switch

public enum LogLevel: Int {

    case Error = 0

    case Warning

    case Info

    case Debug

    case Verbose

    var prefix : String {

        get {

            switch self {

            case .Error: return "E"

            case .Warning:  return "W"

            case .Info:     return "I"

            case .Debug:    return "D"

            case .Verbose:  return "V"

            }

        }
 }

}

//回到上一頁(不管是present或push出來的vc)

dynamic func popToPrevious() {

        logInfo(TAG, "popToPrevious")

        if self.parentNavigationController != nil {

            //self.parentNavigationController是自己創的，看有沒有被給值

            self.parentNavigationController?.popViewControllerAnimated(true)

        } else if let navigation = self.navigationController {

            navigation.popViewControllerAnimated(true)

        } else if self.presentingViewController != nil

            && (self.presentingViewController is NewLoginViewController) == false {

                self.dismissViewControllerAnimated(true, completion: nil)

        }

    }

//在textView中加入圖片

var textAttachment = NSTextAttachment()

        textAttachment.image = UIImage.scaleToSize(image, size: CGSize(width: UIMessageTheme.AvatarTitle.size, height: UIMessageTheme.AvatarTitle.size))

        let imageString = NSAttributedString(attachment: textAttachment)

        var mas = NSMutableAttributedString(attributedString: inputTextField.attributedText)

        mas.replaceCharactersInRange(NSMakeRange(mas.length, 0), withAttributedString: imageString)

        self.inputTextField.attributedText = mas;

//偵測status bar點擊事件(寫在AppDelegate中)

public override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {

        super.touchesBegan(touches, withEvent: event)

        let touchesSet = touches as NSSet

        if let touch = touchesSet.anyObject() as? UITouch {

            let location = touch.locationInView(self.window)

            //你偵測的高度

            if location.y > 0 && location.y < 20 {

                self.touchStatusBar()

            }

        }

    }

    private func touchStatusBar() {

        NSNotificationCenter.defaultCenter().postNotificationName(DefaultConfig.STATUS_BAR_CLICK, object: nil)

    }

//設定UITextView的文字邊界

self.yourTextView.textContainerInset = UIEdgeInsets(top: 10.5, left: 9, bottom: 9.5, right: 15)

//加上模糊效果

//should import UIKit

func insertBlurView (view: UIView,  style: UIBlurEffectStyle) {

    view.backgroundColor = UIColor.clearColor()

    var blurEffect = UIBlurEffect(style: style)

    var blurEffectView = UIVisualEffectView(effect: blurEffect)       

    blurEffectView.frame = view.bounds

    view.insertSubview(blurEffectView, atIndex: 0)

}

//取得現在時間（原來是用[NSDate date]）

let date = NSDate()

//去掉空尾空白和換行

let dataString = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())

//data to string (utf8)

let data = command.dataUsingEncoding(NSUTF8StringEncoding)

//data to string (utf8)

let string = String(data: data!, encoding: NSUTF8StringEncoding)

//移除present出來的viewController

func dismissViewController(viewController: UIViewController, animated: Bool) {

    if viewController.isBeingDismissed() || viewController.isBeingPresented() {

        dispatch_async(dispatch_get_main_queue()) {

            dismissViewController(viewController, animated: animated)

        }

        return

    }

    if viewController.presentingViewController != nil {

        viewController.dismissViewControllerAnimated(animated, completion: nil)

    }

}

// UIColor Extension

    // 自定義color

    class func styleDarkColor() -> UIColor {

        return UIColor.hexToColor(0xFF008CEE)

    }

    class func hexToColor(hex: UInt32) -> UIColor {

        return UIColor(red: CGFloat((hex & 0xFF0000) >> 16) / 255, green: CGFloat((hex & 0xFF00) >> 8) / 255 ,

            blue: CGFloat(hex & 0xFF) / 255 , alpha: CGFloat((hex & 0xFF000000) >> 24) / 255)

    }

    // 十六進制String轉UIColor

    class func hexStringToColor(hexString: String) -> UIColor {

        var rgbValue: UInt32 = 0

        let scanner = NSScanner(string: hexString)

        scanner.scanLocation = 0

        scanner.scanHexInt(&rgbValue)

        return UIColor(red: CGFloat((rgbValue & 0xFF0000) >> 16)/255.0,

            green: CGFloat((rgbValue & 0xFF00) >> 8)/255.0,

            blue: CGFloat(rgbValue & 0xFF)/255.0,

            alpha: 1.0)

    }

    // 以這個顏色產生一個長度為1的小圖(在button好用)

    func tinyImage() -> UIImage {

        let rect = CGRectMake(0.0, 0.0, 1.0, 1.0)

        UIGraphicsBeginImageContext(rect.size)

        let context = UIGraphicsGetCurrentContext()

        CGContextSetFillColorWithColor(context, self.CGColor)

        CGContextFillRect(context, rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return image

    }

//改變navigationController的顏色

    //navigation bar

    navigationController.navigationBar.barTintColor = UIColor.yellowColor()

    //navigation bar text

    navigationController.navigationBar.titleTextAttributes =  [UITextAttributeTextColor: UIColor.yellowColor()]

//改變tabBarController的顏色

    //tab bar

    tabBarController.tabBar.barTintColor = UIColor.yellowColor()

    //tab bar text

    tabBarController.tabBar.tintColor = UIColor.yellowColor()

//不讓app進入休眠

UIApplication.sharedApplication().idleTimerDisabled = true

同時最好去實作appDelegate裡面的func applicationWillResignActive(application: UIApplication) { ... }
把可以發生的中斷事件都處理好，例如phone call、SMS等。

//客製化UITextField的輸入鍵盤
    //換掉inputView就行

        yourTextField.inputView = yourPickerView

    //換回來系統預設的

        yourTextField.inputView = nil

        yourTextField.reloadInputViews()

    //這是換掉鍵盤上面那一條控制用的Bar

        yourTextField.inputAccessoryView = yourCustomAccessoryView

//使用其他預設的鍵盤－改變UIKeyboardType

self.phoneTextField.keyboardType = .PhonePad

self.emailTextField.keyboardType = .EmailAddress

// UIButton預設是置中對齊，如果要改成向左就這樣設

yourButton.contentHorizontalAlignment = .Left

//object to data

let yourViewToData = NSKeyedArchiver.archivedDataWithRootObject(yourView)
if let yourViewFromData = NSKeyedUnarchiver.unarchiveObjectWithData(yourViewToData) as? UIView {
  // Do what you want with your view
}

邁向一萬小時成長之路

2015年3月10日星期二

swift程式碼小碎片筆記

沒有留言:

張貼留言

2015年3月10日 星期二

swift程式碼小碎片筆記

沒有留言:

張貼留言

2015年3月10日星期二