Optional
출처 : 옵셔널 (Optional)
//: Playground - noun: a place where people can play
import UIKit
var email: String?
print(email) // nil
nickname = "bluexmas"
print(nickname) // Optional("bluexmas")
var str = "Hello, playground"
var name:Optional<string> = "name"
var name2:String? = "name2"
var name4:ImplicitlyUnwrappedOptional<string> = "name4";
var name3:String! = "name3"
print() name2 값이 nil 아니면 name2값 출력, name2의 값이 nil 및 경우 ?? 뒤에 있는 값 출력
if name != nil {
print(name!)
}
if val n = name {
print(n)
}
if let n = name {
print(n)
}
var text1:String = "abc"
Int(test1) // nil
var test:String = "123"
print(Int(test)! + 10)
nil 전달 함수
var lampOn:Bool? = false
func lampOnOffRemove(isOn : Bool?) {
if let onOff = isOn {
self.lampOn = onOff
self.lampImageView.image = UIImage(named : onOff ? "lamp-on.png" : "lamp-off.png")
} else {
self.lampOn = nil
self.lampImageView.image = UIImage(named : "lamp-remove.png")
}
}
@IBAction func lampOffClicked(_ sender: AnyObject) {
if lampOn! { // <-- 컴파일시 느낌표(!) 있어야 컴파일이 되고, 값이 nil 인 경우 런타임시 오류 발생
//
} else {
//
}
}
WebView HTML 문자열 로딩
@IBAction func HTMLClicked(_ sender: AnyObject) {
let htmlString = "HTML String
String 변수를 이용한 웹페이지
애플 홈페이지로 이동
"
webView.loadHTMLString(htmlString, baseURL: nil)
}
WebView HTML 파일 로딩
func loadPageWithUrlString(urlString : String) {
if let url = URL(string : urlString) {
webView.loadRequest(URLRequest(url: url))
}
}
@IBAction func fileClicked(_ sender: AnyObject) {
if let path = Bundle.main.path(forResource: "Sample", ofType : "html") {
loadPageWithUrlString(urlString: path)
}
}
WebView Delegate
class ViewController: UIViewController, UIWebViewDelegate {
@IBOutlet weak var webView: UIWebView!
@IBOutlet weak var loadingIndicator: UIActivityIndicatorView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.webView.delegate = self
}
public func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool
{
guard let urlString = request.url?.absoluteString else {
return true;
}
print(request.url?.absoluteString ?? "")
if urlString.contains("daum.net") {
return false;
}
return true;
}
public func webViewDidStartLoad(_ webView: UIWebView)
{
loadingIndicator.startAnimating()
}
public func webViewDidFinishLoad(_ webView: UIWebView)
{
loadingIndicator.stopAnimating()
}
public func webView(_ webView: UIWebView, didFailLoadWithError error: Error)
{
print(error.localizedDescription)
loadingIndicator.stopAnimating()
}
포커스 이동
// 텍스트필드 컨트롤에 포커서를 줘서 키패드가 자동으로 올라오도록 함
self.urlTextField.becomeFirstResponder()
Objective-C main 함수
출처 : The App Life Cycle
//
// main.m
// study2
//
// Created by Mac on 2017. 5. 27..
// Copyright © 2017년 Mac. All rights reserved.
//
#import <uikit uikit.h="">
#import "AppDelegate.h"
int main(int argc, char * argv[]) {
@autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
UIImageView 확대
@IBAction func OnBtnScaleClick(_ sender: UIButton) {
imgLamp.frame.size.width *= 1.2
imgLamp.frame.size.height *= 1.2
}
형변환
@IBAction func typeCast(_ sender: AnyObject) {
if let tmpButton = sender as? UIButton {
tmpButton.setTitle("확대2", for: .normal)
}
}
loadImage 함수 구현
func loadImage(fileName : String, fileType : String) -> UIImage? {
if let path = Bundle.main.path(forResource: fileName, ofType: fileType) {
return UIImage(contentsOfFile : path)
} else {
return nil;
}
}
@IBAction func OnRadio1Change(_ sender: UISwitch) {
imgLamp.image = loadImage( fileName : sender.isOn ? "lamp_on.png" : "lamp_off.png", fileType : "png" )
}
TextField Delegate
public func textFieldShouldReturn(_ textField: UITextField) -> Bool // called when 'return' key pressed. return NO to ignore.
{
loadPageWithUrlString(urlString: urlTextField.text ?? "")
// 포커스 해지
view.endEditing(true)
return true;
}
배열추가, String format, 이미지 변경
var flowerArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
for i in 1...6 {
flowerArray.append( String(format : "%02d.png", i))
}
}
@IBAction func onBtnNextClick(_ sender: UIButton) {
if sender.currentTitle == "이전" {
current_img_index -= 1
} else {
current_img_index += 1
}
if current_img_index >= flowerArray.count {
current_img_index = 0
}
if current_img_index < 0 {
current_img_index = flowerArray.count - 1
}
imgLamp.image = UIImage(named : flowerArray[current_img_index])
}
Timer
// 1초에 한번씩 호출
Timer.scheduledTimer(withTimeInterval: 1, repeats: true, block: {
(timer) -> Void in
// NSLog("%G", #function)
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy M d HH:mm:ss"
self.lblCurrentTime.text = "현재시간 : " + dateFormatter.string(from : Date())
})
UIAlertController
override func viewDidAppear(_ animated: Bool) {
/*
let messageBox = UIAlertView(title : "알림", message : "메시지", delegate : nil, cancelButtonTitle : "OK")
messageBox.show()
*/
let messageBox = UIAlertController(title: "알림", message: "메시지", preferredStyle: .alert)
messageBox.addAction(UIAlertAction(title : "OK", style : .default, handler : {
(action) -> Void in
print("OK 선택")
}))
messageBox.addTextField(configurationHandler: {
(textfield) in
textfield.backgroundColor = UIColor.yellow
})
present(messageBox, animated : true, completion : nil)
}
picker
import UIKit
class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {
@IBOutlet weak var imagePickerView: UIPickerView!
@IBOutlet weak var selectedItemLable: UILabel!
@IBOutlet weak var selectedImageView: UIImageView!
var mArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
imagePickerView.dataSource = self
imagePickerView.delegate = self
for i in 1...6 {
mArray.append(String(format: "%02d", i))
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// picker 열의 개수
public func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
// picker 행의 개수
public func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return mArray.count;
}
/*
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return mArray[row]
}*/
// picker 행의 높이 설정
public func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat
{
return 100;
}
// picker 행을 이미지로 표시
public func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView
{
let imageView = UIImageView(frame:CGRect(x:0, y:0, width:100, height:100));
imageView.image = UIImage(named : mArray[row])
return imageView
}
// 선택이벤트
public func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
selectedItemLable.text = "선택 = " + mArray[row]
selectedImageView.image = UIImage(named : mArray[row])
}
}
이미지 비동기 로딩
if let urlString = movieArray[indexPath.row].thumbnailUrl,
let url = URL(string : urlString)
{
do {
/*
// 동기방식
let imageData = try Data(contentsOf: url)
cell.thumbnailImageView.image = UIImage(data : imageData)
*/
} catch {
}
// 비동기방식
let task = URLSession.shared.dataTask(with: url) {
(data, response, error) -> Void in
if let imageData = data {
DispatchQueue.main.async {
cell.thumbnailImageView.image = UIImage(data : imageData)
}
}
}
task.resume()
}
동영상 플레이
func playVideo(url : URL) {
let playerVC = AVPlayerViewController()
let player = AVPlayer(url: url)
playerVC.player = player
present(playerVC, animated: true, completion: {
playerVC.player?.play()
})
}
