bestswifter · zyphs21 · Nov 8, 2017
diff --git a/CornerRadius/CornerRadius.xcodeproj/project.pbxproj b/CornerRadius/CornerRadius.xcodeproj/project.pbxproj
@@ -423,6 +423,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "CornerRadius/CornerRadius-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -436,6 +437,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = NEU.CornerRadius;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OBJC_BRIDGING_HEADER = "CornerRadius/CornerRadius-Bridging-Header.h";
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};

diff --git a/CornerRadius/CornerRadius/AppDelegate.swift b/CornerRadius/CornerRadius/AppDelegate.swift
@@ -13,31 +13,29 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 
     var window: UIWindow?
 
-
-    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
-        // Override point for customization after application launch.
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
         return true
     }
 
-    func applicationWillResignActive(application: UIApplication) {
+    func applicationWillResignActive(_ application: UIApplication) {
         // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
         // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
     }
 
-    func applicationDidEnterBackground(application: UIApplication) {
+    func applicationDidEnterBackground(_ application: UIApplication) {
         // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
         // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
     }
 
-    func applicationWillEnterForeground(application: UIApplication) {
+    func applicationWillEnterForeground(_ application: UIApplication) {
         // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
     }
 
-    func applicationDidBecomeActive(application: UIApplication) {
+    func applicationDidBecomeActive(_ application: UIApplication) {
         // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
     }
 
-    func applicationWillTerminate(application: UIApplication) {
+    func applicationWillTerminate(_ application: UIApplication) {
         // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
     }
 

diff --git a/CornerRadius/CornerRadius/CustomTableViewCell.swift b/CornerRadius/CornerRadius/CustomTableViewCell.swift
@@ -10,18 +10,18 @@ import UIKit
 
 class CustomTableViewCell: UITableViewCell {
 
-    let imgView1 = UIImageView(frame: CGRectMake(5, 10, 20, 21))
-    let imgView2 = UIImageView(frame: CGRectMake(55, 10, 20, 21))
-    let view = UIView(frame: CGRectMake(150,10,40,21))
-    let label = UILabel(frame: CGRectMake(250,10,80,21))
+    let imgView1 = UIImageView(frame: CGRect(x: 5, y: 10, width: 20, height: 21))
+    let imgView2 = UIImageView(frame: CGRect(x: 55, y: 10, width: 20, height: 21))
+    let view = UIView(frame: CGRect(x: 150, y: 10, width: 40, height: 21))
+    let label = UILabel(frame: CGRect(x: 250, y: 10, width: 80, height: 21))
 
     override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
         super.init(style: style, reuseIdentifier: reuseIdentifier)
 
         self.contentView.addSubview(imgView1)
         self.contentView.addSubview(imgView2)
 
-        view.backgroundColor = UIColor.brownColor()
+        view.backgroundColor = UIColor.brown
         view.layer.cornerRadius = 5
 
         self.contentView.addSubview(view)
@@ -30,7 +30,7 @@ class CustomTableViewCell: UITableViewCell {
 //        label.kt_addCorner(radius: 8)
         label.layer.cornerRadius = 5
         label.text = "123"
-        label.backgroundColor = UIColor.brownColor()
+        label.backgroundColor = UIColor.brown
         self.contentView.addSubview(label)
     }
 
@@ -43,18 +43,18 @@ class CustomTableViewCell: UITableViewCell {
         // Initialization code
     }
 
-    func setupContent(imgName imgName: String) {
+    func setupContent(imgName: String) {
         imgView1.image = UIImage(named: imgName)
         imgView2.image = UIImage(named: imgName)
 
         // 下面两行取消注释后试试
-//        imgView1.kt_addCorner(radius: 5)
-//        imgView2.kt_addCorner(radius: 5)
+//        imgView1.kt_imageViewAddCorner(radius: 5)
+//        imgView2.kt_imageViewAddCorner(radius: 5)
     }
 
-    override func setSelected(selected: Bool, animated: Bool) {
+    override func setSelected(_ selected: Bool, animated: Bool) {
         super.setSelected(selected, animated: animated)
-
+        
         // Configure the view for the selected state
     }
 

diff --git a/CornerRadius/CornerRadius/KtCorner.swift b/CornerRadius/CornerRadius/KtCorner.swift
@@ -9,25 +9,25 @@
 import Foundation
 import UIKit
 
-private func roundbyunit(num: Double, inout _ unit: Double) -> Double {
+private func roundbyunit(_ num: Double, _ unit: inout Double) -> Double {
     let remain = modf(num, &unit)
     if (remain > unit / 2.0) {
         return ceilbyunit(num, &unit)
     } else {
         return floorbyunit(num, &unit)
     }
 }
-private func ceilbyunit(num: Double, inout _ unit: Double) -> Double {
+private func ceilbyunit(_ num: Double, _ unit: inout Double) -> Double {
     return num - modf(num, &unit) + unit
 }
 
-private func floorbyunit(num: Double, inout _ unit: Double) -> Double {
+private func floorbyunit(_ num: Double, _ unit: inout Double) -> Double {
     return num - modf(num, &unit)
 }
 
 private func pixel(num: Double) -> Double {
     var unit: Double
-    switch Int(UIScreen.mainScreen().scale) {
+    switch Int(UIScreen.main.scale) {
     case 1: unit = 1.0 / 1.0
     case 2: unit = 1.0 / 2.0
     case 3: unit = 1.0 / 3.0
@@ -37,50 +37,60 @@ private func pixel(num: Double) -> Double {
 }
 
 extension UIView {
-    func kt_addCorner(radius radius: CGFloat) {
-        self.kt_addCorner(radius: radius, borderWidth: 1, backgroundColor: UIColor.clearColor(), borderColor: UIColor.blackColor())
+    func kt_addCorner(radius: CGFloat) {
+        self.kt_addCorner(radius: radius, borderWidth: 1, backgroundColor: UIColor.clear, borderColor: UIColor.black)
     }
 
-    func kt_addCorner(radius radius: CGFloat,
+    func kt_addCorner(radius: CGFloat,
                       borderWidth: CGFloat,
                       backgroundColor: UIColor,
                       borderColor: UIColor) {
         let imageView = UIImageView(image: kt_drawRectWithRoundedCorner(radius: radius,
-                                    borderWidth: borderWidth,
-                                    backgroundColor: backgroundColor,
-                                    borderColor: borderColor))
-        self.insertSubview(imageView, atIndex: 0)
+                                                                        borderWidth: borderWidth,
+                                                                        backgroundColor: backgroundColor,
+                                                                        borderColor: borderColor))
+        self.insertSubview(imageView, at: 0)
     }
 
-    func kt_drawRectWithRoundedCorner(radius radius: CGFloat,
+    func kt_drawRectWithRoundedCorner(radius: CGFloat,
                                       borderWidth: CGFloat,
                                       backgroundColor: UIColor,
                                       borderColor: UIColor) -> UIImage {
-        let sizeToFit = CGSize(width: pixel(Double(self.bounds.size.width)), height: Double(self.bounds.size.height))
+        let sizeToFit = CGSize(width: pixel(num: Double(self.bounds.size.width)), height: Double(self.bounds.size.height))
         let halfBorderWidth = CGFloat(borderWidth / 2.0)
 
-        UIGraphicsBeginImageContextWithOptions(sizeToFit, false, UIScreen.mainScreen().scale)
-        let context = UIGraphicsGetCurrentContext()
-
-        CGContextSetLineWidth(context, borderWidth)
-        CGContextSetStrokeColorWithColor(context, borderColor.CGColor)
-        CGContextSetFillColorWithColor(context, backgroundColor.CGColor)
+        UIGraphicsBeginImageContextWithOptions(sizeToFit, false, UIScreen.main.scale)
+        guard let context = UIGraphicsGetCurrentContext() else {
+            UIGraphicsEndImageContext()
+            return UIImage()
+        }
+        context.setLineWidth(borderWidth)
+        context.setStrokeColor(borderColor.cgColor)
+        context.setFillColor(backgroundColor.cgColor)
 
         let width = sizeToFit.width, height = sizeToFit.height
-        CGContextMoveToPoint(context, width - halfBorderWidth, radius + halfBorderWidth)  // 开始坐标右边开始
-        CGContextAddArcToPoint(context, width - halfBorderWidth, height - halfBorderWidth, width - radius - halfBorderWidth, height - halfBorderWidth, radius)  // 右下角角度
-        CGContextAddArcToPoint(context, halfBorderWidth, height - halfBorderWidth, halfBorderWidth, height - radius - halfBorderWidth, radius) // 左下角角度
-        CGContextAddArcToPoint(context, halfBorderWidth, halfBorderWidth, width - halfBorderWidth, halfBorderWidth, radius) // 左上角
-        CGContextAddArcToPoint(context, width - halfBorderWidth, halfBorderWidth, width - halfBorderWidth, radius + halfBorderWidth, radius) // 右上角
-
-        CGContextDrawPath(UIGraphicsGetCurrentContext(), .FillStroke)
+        context.move(to: CGPoint(x: width - halfBorderWidth, y: radius + halfBorderWidth))  // 开始坐标右边开始
+        context.addArc(tangent1End: CGPoint(x: width - halfBorderWidth, y: height - halfBorderWidth),
+                       tangent2End: CGPoint(x: width - radius - halfBorderWidth, y: height - halfBorderWidth),
+                       radius: radius)  // 右下角
+        context.addArc(tangent1End: CGPoint(x: halfBorderWidth, y: height - halfBorderWidth),
+                       tangent2End: CGPoint(x: halfBorderWidth, y: height - radius - halfBorderWidth),
+                       radius: radius)  // 左下角
+        context.addArc(tangent1End: CGPoint(x: halfBorderWidth, y: halfBorderWidth),
+                       tangent2End: CGPoint(x: width - halfBorderWidth, y: halfBorderWidth),
+                       radius: radius) // 左上角
+        context.addArc(tangent1End: CGPoint(x: width - halfBorderWidth, y: halfBorderWidth),
+                       tangent2End: CGPoint(x: width - halfBorderWidth, y: radius + halfBorderWidth),
+                       radius: radius) // 右上角
+        context.drawPath(using: .fillStroke)
         let output = UIGraphicsGetImageFromCurrentImageContext()
         UIGraphicsEndImageContext()
-        return output
+        return output ?? UIImage()
     }
 }
 
 extension UIImageView {
+    /*
     /**
      / !!!只有当 imageView 不为nil 时，调用此方法才有效果
 
@@ -91,23 +101,35 @@ extension UIImageView {
 //        self.image = self.image?.imageAddCornerWithRadius(radius, andSize: self.bounds.size)
         self.image = self.image?.kt_drawRectWithRoundedCorner(radius: radius, self.bounds.size)
     }
+    */
+
+    // Note: In Swift 4: Declarations in extensions cannot override. So I rename the function
+    func kt_imageViewAddCorner(radius: CGFloat) {
+        // 被注释的是图片添加圆角的 OC 写法
+        // self.image = self.image?.imageAddCornerWithRadius(radius, andSize: self.bounds.size)
+        self.image = self.image?.kt_drawRectWithRoundedCorner(radius: radius, self.bounds.size)
+    }
 }
 
 extension UIImage {
-    func kt_drawRectWithRoundedCorner(radius radius: CGFloat, _ sizetoFit: CGSize) -> UIImage {
+    func kt_drawRectWithRoundedCorner(radius: CGFloat, _ sizetoFit: CGSize) -> UIImage {
         let rect = CGRect(origin: CGPoint(x: 0, y: 0), size: sizetoFit)
 
-        UIGraphicsBeginImageContextWithOptions(rect.size, false, UIScreen.mainScreen().scale)
-        CGContextAddPath(UIGraphicsGetCurrentContext(),
-            UIBezierPath(roundedRect: rect, byRoundingCorners: UIRectCorner.AllCorners,
-                cornerRadii: CGSize(width: radius, height: radius)).CGPath)
-        CGContextClip(UIGraphicsGetCurrentContext())
+        UIGraphicsBeginImageContextWithOptions(rect.size, false, UIScreen.main.scale)
+        guard let context = UIGraphicsGetCurrentContext() else {
+            UIGraphicsEndImageContext()
+            return UIImage()
+        }
+        context.addPath(UIBezierPath(roundedRect: rect, byRoundingCorners: .allCorners,
+                                     cornerRadii: CGSize(width: radius, height: radius)).cgPath)
+        context.clip()
 
-        self.drawInRect(rect)
-        CGContextDrawPath(UIGraphicsGetCurrentContext(), .FillStroke)
+        self.draw(in: rect)
+        context.drawPath(using: .fillStroke)
         let output = UIGraphicsGetImageFromCurrentImageContext()
         UIGraphicsEndImageContext()
 
-        return output
+        return output ?? UIImage()
     }
 }
+
diff --git a/CornerRadius/CornerRadius/ViewController.swift b/CornerRadius/CornerRadius/ViewController.swift
@@ -9,39 +9,43 @@
 import UIKit
 
 class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
-    let table = UITableView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.size.width, UIScreen.mainScreen().bounds.size.height))
+
+    let identifier = "tableviewcell"
+
+    let table = UITableView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height))
+
     override func viewDidLoad() {
         super.viewDidLoad()
 
         table.delegate = self
         table.dataSource = self
+        table.register(CustomTableViewCell.self, forCellReuseIdentifier: identifier)
 
         view.addSubview(table)
         // Do any additional setup after loading the view, typically from a nib.
     }
-
+    
     override func didReceiveMemoryWarning() {
         super.didReceiveMemoryWarning()
         // Dispose of any resources that can be recreated.
     }
-
-    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
-        let identifier = "tableviewcell"
-        table.registerClass(CustomTableViewCell.self, forCellReuseIdentifier: identifier)
-        let cell = table.dequeueReusableCellWithIdentifier(identifier, forIndexPath: indexPath) as? CustomTableViewCell
-
-        cell?.selectionStyle = .None
+
+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        let cell = tableView.dequeueReusableCell(withIdentifier: identifier, for: indexPath) as? CustomTableViewCell
+        cell?.selectionStyle = .none
         cell?.setupContent(imgName: "photo")
 
         return cell!
     }
 
-    func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
+    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
         return 40
     }
 
-    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         return 100
     }
 }
 
+
+