iOS測試IPv6環境

 簡述：分享Mac的WiFi給手機。打開分享時，需按住Option，分享才會有NAT64。

詳細方法，參考這篇的Test for IPv6 DNS64/NAT64 Compatibility Regularly。

值得注意，用USB線分享的話，會是IPv4+IPv6

Swift Decodable 找不到key時，使用預設值

使用JSONDecoder時，如果找不到Key值，錯誤如下

▿ DecodingError
  ▿ keyNotFound : 2 elements
    - .0 : CodingKeys(stringValue: "b", intValue: nil)
    ▿ .1 : Context
      - codingPath : 0 elements
      - debugDescription : "No value associated with key CodingKeys(stringValue: \"b\", intValue: nil) (\"b\")."
      - underlyingError : nil

其實只要利用KeyedDecodingContainer的decode(type:forKey)就可以解決這問題

protocol Init {
    init()
}

extension KeyedDecodingContainer {
    func decode<T: Codable & Init>(_ type: T.Type,
                forKey key: Key) throws -> T {
        try decodeIfPresent(type, forKey: key) ?? .init()
    }
}

之後只要將Codable後面，加上Init這個protocal就可以了

enum B: Int, Codable {
    case one = 1
    case two = 2
}


extension B: Init {
    init() {
        self = .one
    }
}

用swift讀寫NTag

1. 在info.plist中，加入Privacy - NFC Scan Usage Description
2. 在Capabilities 加入Near Field Communication Tag Reading
   
3. 掃描

   func startScan() {

           let session = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: false)

           session.alertMessage = "Hold your iPhone near an NFC transit card."

           session.begin()

   }

4. 連線，更新payload

   func readerSession(_ session: NFCNDEFReaderSession, didDetect tags: [NFCNDEFTag]) {

       guard

           let sms = "場所代碼：111111111111111 本次實聯簡訊限防疫目的使用。".addingPercentEncoding(withAllowedCharacters: .urlHostAllowed),

           let payload = NFCNDEFPayload.wellKnownTypeURIPayload(string: "sms:1922&body=\(sms)"),

           let tag = tags.first

       else {

           session.invalidate(errorMessage: "Could not process tag.")

           return

       }

       session.connect(to: tag) { error in

           guard error == nil else {

               session.invalidate(errorMessage: "Could not connect to tag.")

               return

           }

           tag.queryNDEFStatus { status, capacity, error in

               guard error == nil else {

                   session.invalidate(errorMessage: "Could not query status of tag.")

                   return

               }

               

               switch status {

               case .notSupported:

                   session.invalidate(errorMessage: "Tag is not supported.")

               case .readOnly:

                   session.invalidate(errorMessage: "Tag is only readable.")

               case .readWrite:

                   let messge = NFCNDEFMessage.init(records: [payload])

                   tag.writeNDEF(messge) { error in

                       if error != nil {

                           session.invalidate(errorMessage: "Failed to write message.")

                       } else {

                           session.alertMessage = "Successfully configured tag."

                           session.invalidate()

                       }

                   }

                   

               @unknown default:   session.invalidate(errorMessage: "Unknown status of tag.")

               }

           }

       }

   }

PS.找不到 Near Field Communication Tag Reading ，請切換開發者帳號到付費帳號

ARKit(SpriteKit) 臉部角度追蹤

1. 建立😘 。由於前鏡頭左右相反，所以X軸要反向。

   let labelNode = SKLabelNode(text: "😘")

   labelNode.horizontalAlignmentMode = .center

   labelNode.verticalAlignmentMode = .center

   labelNode.xScale = -1

2. 須將😘放入SKTransformNode，做後續的3D轉換。
   

   let face = SKTransformNode()

   face.addChild(labelNode)

   self.face = face

3. 更新時，SKTransformNode再依據ARFaceAnchor旋轉
   

   let rotate = faceAnchor.transform.rotate

   face?.setRotationMatrix(rotate)

4. 最後，記得將node轉回來，否則貼圖會是反的

完整程式

ARKit(SceneKit) 更新模型臉部表情

ARKit(SceneKit) 臉部貼圖

1. 修改Tracking and Visualizing Faces範例中的貼圖『wireframeTexture.png』
2. 指定ARSCNFaceGeometry的貼圖

   faceMesh?.firstMaterial?.diffuse.contents = UIImage(named: "wireframeTexture")

ARKit(SceneKit) 臉部表情追蹤

1.  建立臉部追蹤

// Create a session configuration

 let configuration = ARFaceTrackingConfiguration()

// Run the view's session

sceneView.session.run(configuration)

2.  建立臉部模型

func renderer(_ renderer: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode? {

    if anchor is ARFaceAnchor {

        let faceMesh = ARSCNFaceGeometry(device: sceneView.device!)

        faceMesh?.firstMaterial?.lightingModel = .physicallyBased

        let node = SCNNode(geometry: faceMesh)

        return node

    } else {

        return nil

    }

}

3.  更新臉部表情

func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) {

    if let faceAnchor = anchor as? ARFaceAnchor, let faceGeometry = node.geometry as? ARSCNFaceGeometry {

        faceGeometry.update(from: faceAnchor.geometry)

    }

}

RealityKit 判斷手指觸摸物件

1. 用Reality Composer編輯物件『屬性』，勾選『物理效果』『加入』
2. 將ARFrame.capturedImage轉成CVPixelBuffer

   func session(_ session: ARSession, didUpdate frame: ARFrame) {

           guard let arView = arView else {return}

           // Do not enqueue other buffers for processing while another Vision task is still running.

           // The camera stream has only a finite amount of buffers available; holding too many buffers for analysis would starve the camera.

           guard currentBuffer == nil, case .normal = frame.camera.trackingState else {

               return

           }

           // Retain the image buffer for Vision processing.

           let currentBuffer = frame.capturedImage

   }

3. 利用Vision偵測食指
   

   let requestHandler = VNImageRequestHandler(cvPixelBuffer: currentBuffer, orientation: orientation)

   visionQueue.async {

           do {

                   // Perform VNDetectHumanHandPoseRequest

                   try requestHandler.perform([self.handPoseRequest])

                   // Continue only when a hand was detected in the frame.

                   // Since we set the maximumHandCount property of the request to 1, there will be at most one observation.

                   guard let observation = self.handPoseRequest.results?.first else {

                       return

                   }

                   // Get points for index finger.

                   let indexFingerPoints = try observation.recognizedPoints(.indexFinger)

                   // Look for tip points.

                   guard let indexTipPoint = indexFingerPoints[.indexTip] else {

                       return

                   }

                   // Ignore low confidence points.

                   guard indexTipPoint.confidence > 0.3 else {

                       return

                   }

                   

                   

           } catch {

                   print("Error: Vision request failed with error \"\(error)\"")

           }

   }

4. 將Vision的座標轉成ARView的座標
   

   // Convert points from Vision coordinates to ARView coordinates.

   let point = indexTipPoint.location

   let tip = CGPoint(x: point.x * width, y: (1 - point.y) * height)

sample code

RealityKit 判斷物件點擊方法2

1. 用Reality Composer編輯物件『屬性』，勾選『物理效果』『加入』
2. 替arView加上手勢功能
   

   arView.addGestureRecognizer(

         UITapGestureRecognizer(

               target: xxxx,

               action: #selector(XXXX.handleTap(recognizer:))

       )

   )

3. 
   

   @objc func handleTap(recognizer: UITapGestureRecognizer) {

           let tapLocation = recognizer.location(in: arView)

           let entity = arView.entity(at: tapLocation)

           guard entity == boxAnchor?.steelBox else { return }

           // entity 即點擊物件

   }

RealityKit 判斷物件點擊方法1

 直接用Reality Composer編輯物件行為

1. 選取物件
2. 顯示行為(⌥⌘B)
3. 加入行為『點按與反轉』

建立一個空的MapView

1. 使用satellite，除了地形圖，沒有多餘的文字。
2. 建一個MKTileOverlay，利用canReplaceMapContent隱藏地圖。

在Heroku上發佈MochiWeb

注意：

1. 官方https://github.com/heroku/heroku-buildpack-erlang.git過舊（OTP和cebar），所以需要替代方案
2. Heroku的port是亂數產生，所以需要動態拿到port

參考

SWIProlog on TextMate

因TextMate提供的Plugin有問提，只好自己再改一下

iOS hot reloading

1. 安裝 InjectionIII 並啟動
2. 打開 XCode 和 專案
3. 在appDelegate加入

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        // Override point for customization after application launch.z

        #if DEBUG

        #if targetEnvironment(simulator)

        #if os(iOS)

        Bundle(path: "/Applications/InjectionIII.app/Contents/Resources/iOSInjection.bundle")?.load()

        #elseif os(tvOS)

        Bundle(path: "/Applications/InjectionIII.app/Contents/Resources/tvOSInjection.bundle")?.load()

        #endif

        #elseif os(macOS)

        Bundle(path: "/Applications/InjectionIII.app/Contents/Resources/macOSInjection.bundle")?.load()

        #endif

        #endif

        return true

    }

PS.
已經秀出來的view並未改變。但是，新present出的view確實已經改變

如需要改變已秀出來的view，需在每個controller上實作

@objc func injected() {

    // 可馬上更新的code

}

建議的懶人法

    @objc func injected() {

        // 移除全部vc/view

        if self.childViewControllers.count > 0{

            let viewControllers:[UIViewController] = self.childViewControllers

            for viewContoller in viewControllers{

                viewContoller.willMove(toParentViewController: nil)

                viewContoller.view.removeFromSuperview()

                viewContoller.removeFromParentViewController()

            }

        }

        

        configureView()

    }

    

    func configureView() {

        

    }

    

    override func viewDidLoad() {

        super.viewDidLoad()

        configureView()

    }

Redux特調

最近花了些時間，寫了一個redux的簡易範例，希望可以幫大家快速入門

原始碼

利用CGContext轉出bitmap點陣字

一直搞不懂bindActionCreators的應用原理，
花了一些時間研究，



參考資料

iOS簡繁互轉

UIAlertController客製化

根據🍎的文件

The UIAlertController class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.

如果不想理他的話，就用以下的方法吧！

1. 打開contentViewController的束縛
   @interface UIAlertController (ContentViewController)
   @property (nonatomic,retain) UIViewController * contentViewController;
   @end
2. 呼喚神秘的contentViewController
   alertController.contentViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "contentViewController")
3. 如果，使用tableview的話，記得加上
   override func viewWillLayoutSubviews() {

       super.viewWillLayoutSubviews()

           

       // make UITableView fit to content's size

       self.preferredContentSize = self.tableView.contentSize

   
   

   }

code

iOS launch image的黑魔法

1. 開一個新專案，在iPhone 7 size是 414x736
   
   
2. 移除LaunchScreen.storyboard，在iPhone 7 size是 320x480
   
   
3. 新增Default-568h@2x.png和Default-568h@3x.png到專案中（就算是 1x1的圖也沒關係，重點是檔名要正確），在iPhone 7 size是 320x58