Open the browser with a URL including Unicode characters 以瀏覽器開啟中文網址

The following example is written with Xcode 6.4. It converts a string with Unicode characters to the NSURL format.

Edit ViewController.swift as below:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {

        super.viewDidLoad()

        

        let button = UIButton(frame: CGRectMake(100, 100, 100, 20))

        button.setTitle("Press", forState: UIControlState.Normal)

        button.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)

        button.setTitleColor(UIColor.cyanColor(), forState: UIControlState.Highlighted)//Set the title color while highlighted

        button.addTarget(self, action: "btnPressed:", forControlEvents: UIControlEvents.TouchUpInside)

        view.addSubview(button)

    }

    

    func btnPressed(sender: UIButton) {

        println("btnPressed")

        

        let string = "https://tw.news.yahoo.com/ios-9-0-1釋出-網友：滑臉書好快喔-083210396.html".stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())

        

        let url = NSURL(string: string!)

        UIApplication.sharedApplication().openURL(url!)//Open the URL in the browser.

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}

After pressing the 'Press' button, the browser is opened with the  URL in Chinese.

NSString rangeOfString - Search for matching characters in a string

Type these codes in the playground:

let theString = "Hello World$$1234567890" as NSString

let range = theString.rangeOfString("$$")

//The result is:

//range.location = 11

//range.length = 2

let string1 = theString.substringToIndex(range.location)

let string2 = theString.substringFromIndex(range.location+range.length)

//The result is:

//string1 = "Hello World"

//string2 = "1234567890"

UIAlertControllerStyle.ActionSheet - Action Sheet since iOS 8

UIActionSheet is deprecated in iOS 8. To use the ActionSheet, it is required to use UIAlertController with UIAlertControllerStyle.ActionSheet.

Now edit ViewController.swift as:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {

        super.viewDidLoad()

        

        let myButton = UIButton(frame: CGRectMake(50, 50, 100, 30))

        myButton.setTitle("Press", forState: UIControlState.Normal)

        myButton.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)

        myButton.setTitleColor(UIColor.cyanColor(), forState: UIControlState.Highlighted)//Set the title color while highlighted

        myButton.addTarget(self, action: "btnPressed:", forControlEvents: UIControlEvents.TouchUpInside)

        view.addSubview(myButton)

    }

    

    func btnPressed(sender: UIButton) {

        println("btnPressed")

        

        let myController = UIAlertController(title: "My Title", message: "My Message", preferredStyle: UIAlertControllerStyle.ActionSheet)

        myController.addAction(UIAlertAction(title: "Option 1", style: UIAlertActionStyle.Default, handler: { action in

            println("Option 1")

        }))

        myController.addAction(UIAlertAction(title: "Option 2", style: UIAlertActionStyle.Default, handler: { action in

            println("Option 2")

        }))

        myController.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: nil))

        presentViewController(myController, animated: true, completion: nil)

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}

The result is:

NSString substringToIndex - Truncate a string and add some characters

This is how to get the first n characters in a string and add extra "..." string to the output string:

import UIKit

let str = "Hello World This is a long string 1234567890."

var strTemp = str as NSString

//Keep the first 30 characters.

strTemp = strTemp.substringToIndex(30)

strTemp = (strTemp as String) + "..."

println(strTemp)

The result:

Hello World This is a long str...

stringByReplacingOccurrencesOfString - Replace characters within a string by other characters

Type these codes in the playground:

import UIKit

let str = "Hello##World##123##!!"

var strTemp : String!

strTemp = str.stringByReplacingOccurrencesOfString("##", withString: "\n", options: NSStringCompareOptions.RegularExpressionSearch, range: nil)

println(strTemp)

The result:

Hello

World

123

!!

Related string function:

componentsSeparatedByCharactersInSet and join - Remove specific characters in a string

CGAffineTransformMakeRotation - Create a horizontal table programmatically

This post has been updated with Xcode 7.3 (Swift 2.2) on April 6, 2016.

1. Edit ViewController.swift as:

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    var tableView : UITableView!

    //Table cell background color

    let colorArray = [UIColor.lightGrayColor(), UIColor.darkGrayColor(), UIColor.yellowColor(), UIColor.cyanColor(), UIColor.purpleColor()]

    

    override func viewDidLoad() {

        super.viewDidLoad()

        

        let frame = CGRectMake(0, view.bounds.height/2, view.bounds.width, view.bounds.height/2)
        //A more correct way is to set the frame 
        //as CGRectMake(0, view.bounds.height/2, 
        //view.bounds.height/2, view.bounds.width) here,
        //i.e. swap the width/height values
        //before rotation.

        tableView = UITableView(frame: frame)

        tableView.delegate = self

        tableView.dataSource = self

        

        //Remove gaps at margins #1

        if tableView.respondsToSelector(Selector("separatorInset")) {

            tableView.separatorInset = UIEdgeInsetsZero;

        }

        

        if tableView.respondsToSelector(Selector("layoutMargins")) {

            tableView.layoutMargins = UIEdgeInsetsZero;

        }

        

        tableView.transform = CGAffineTransformMakeRotation(-CGFloat(M_PI_2))

        //Set the frame size again after rotation.

        tableView.frame = frame

        view.addSubview(tableView)

    }

    

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return 5

    }

    

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

        let cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "myIdentifier")

        

        cell.textLabel?.text = "Cell #\(indexPath.row)"

        cell.detailTextLabel?.text = "Subtitle"

        cell.backgroundColor = colorArray[indexPath.row]

        cell.contentView.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2))

        

        //Remove gaps at margins #2

        if cell.respondsToSelector(Selector("separatorInset")) {

            cell.separatorInset = UIEdgeInsetsZero;

        }

        

        if cell.respondsToSelector(Selector("preservesSuperviewLayoutMargins")) {

            cell.preservesSuperviewLayoutMargins = false;

        }

        

        if cell.respondsToSelector(Selector("layoutMargins")) {

            cell.layoutMargins = UIEdgeInsetsZero;

        }

        

        return cell

    }

    

    func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat{

        return view.bounds.width/3

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}

2. Run the iOS simulator to get the result:

Pass parameters / strings between view controllers programmatically (without using storyboard segues)

1. Create a new file called MyClass.swift as:

class MyClass {

    var string1 : String = ""

    var string2 : String = ""

    static let myInstance = MyClass()

}

2. Modify ViewController.swift as:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {

        super.viewDidLoad()

        

        view.backgroundColor = UIColor.cyanColor()

        

        let myLabel = UILabel(frame: CGRectMake(50, 100, 300, 20))

        myLabel.text = "ViewController"

        view.addSubview(myLabel)

        

        let myButton = UIButton(frame: CGRectMake(50, 200, 100, 20))

        myButton.addTarget(self, action: "btnPressed:", forControlEvents: UIControlEvents.TouchUpInside)

        myButton.setTitle("Button", forState: UIControlState.Normal)

        myButton.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)

        view.addSubview(myButton)

    }

    

    override func viewWillAppear(animated: Bool) {

        super.viewWillAppear(animated)

        

        let myLabelFrom = UILabel(frame: CGRectMake(50, 150, 300, 20))

        myLabelFrom.text = "From 2nd VC:\(MyClass.myInstance.string2)"

        myLabelFrom.tag = 50

        view.addSubview(myLabelFrom)

    }

    

    func btnPressed(sender: UIButton){

        //Remove myLabelFrom label because it will be drawn again in viewWillAppear()

        view.viewWithTag(50)?.removeFromSuperview()

        

        //Set the string to be passed to the second view controller.

        MyClass.myInstance.string1 = "String from VC"

        

        let secondVC = SecondViewController()

        

        //Set view controller transition animation style

        secondVC.modalTransitionStyle = UIModalTransitionStyle.CoverVertical

        self.presentViewController(secondVC, animated: true, completion: nil)

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}

3. Create a new file called SecondViewController.swift as:

import UIKit

class SecondViewController: UIViewController {

    override func viewDidLoad() {

        super.viewDidLoad()

        view.backgroundColor = UIColor.yellowColor()

        

        let myLabelSecond = UILabel(frame: CGRectMake(70, 150, 300, 20))

        myLabelSecond.text = "SecondViewController:"

        view.addSubview(myLabelSecond)

        let myLabelSecondFrom = UILabel(frame: CGRectMake(70, 200, 300, 20))

        myLabelSecondFrom.text = "From VC:\(MyClass.myInstance.string1)"

        view.addSubview(myLabelSecondFrom)

        

        let myButtonSecond = UIButton(frame: CGRectMake(70, 250, 100, 20))

        myButtonSecond.addTarget(self, action: "btnPressedSecond:", forControlEvents: UIControlEvents.TouchUpInside)

        myButtonSecond.setTitle("Back", forState: UIControlState.Normal)

        myButtonSecond.setTitleColor(UIColor.blueColor(), forState: UIControlState.Normal)

        view.addSubview(myButtonSecond)

    }

    func btnPressedSecond(sender: UIButton){

        //Set the string to be passed to the original view controller.

        MyClass.myInstance.string2 = "String from 2nd VC"

        dismissViewControllerAnimated(true, completion: nil)

    }

    

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

    }

}

Run the iOS simulator and the first view controller is shown as:

Press 'Button' and the second view controller with yellow background is shown as:

 After pressing the 'Back' button, the screen returns to the first view controller. The string from the second VC is now displayed.