How to programmatically add a UISegmentedControl to a container view

this one is perfect I tested.....

UIScrollView *scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 435)];
scroll.contentSize = CGSizeMake(320, 700);
scroll.showsHorizontalScrollIndicator = YES;

NSArray *itemArray = [NSArray arrayWithObjects: @"One", @"Two", @"Three", nil];
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:itemArray];
segmentedControl.frame = CGRectMake(35, 200, 250, 50);
segmentedControl.segmentedControlStyle = UISegmentedControlStylePlain;
[segmentedControl addTarget:self action:@selector(MySegmentControlAction:) forControlEvents: UIControlEventValueChanged];
segmentedControl.selectedSegmentIndex = 1;     
[scroll addSubview:segmentedControl];
[segmentedControl release]; 
[self.view addSubview:scroll];

Then add your method in your class.

- (void)MySegmentControlAction:(UISegmentedControl *)segment 
{    
    if(segment.selectedSegmentIndex == 0)
    {
        // code for the first button
    } 
}

For deprecated UISegmentedControlStyle you can take a look on this URL.

Try this link:

ADDING A SEGMENTED CONTROL PROGRAMMATICALLY

Updated:

import UIKit

class ViewController: UIViewController {

  /**
    Loads the view and in our case we override default loadView to provide
    custom SegmentedControl.
  */
  override func loadView() {
      super.loadView()
      self.view.backgroundColor = UIColor.purpleColor()

      println("Main view's loadView() called.")

      // Initialize
      let items = ["Purple", "Green", "Blue"]
      let customSC = UISegmentedControl(items: items)
      customSC.selectedSegmentIndex = 0

      // Set up Frame and SegmentedControl
      let frame = UIScreen.mainScreen().bounds
      customSC.frame = CGRectMake(frame.minX + 10, frame.minY + 50,
                                  frame.width - 20, frame.height*0.1)

      // Style the Segmented Control
      customSC.layer.cornerRadius = 5.0  // Don't let background bleed
      customSC.backgroundColor = UIColor.blackColor()
      customSC.tintColor = UIColor.whiteColor()

      // Add target action method
      customSC.addTarget(self, action: "changeColor:", forControlEvents: .ValueChanged)

      // Add this custom Segmented Control to our view
      self.view.addSubview(customSC)
  }

  /**
    Handler for when custom Segmented Control changes and will change the
    background color of the view depending on the selection.
   */
  func changeColor(sender: UISegmentedControl) {
      println("Change color handler is called.")
      print("Changing Color to ")
      switch sender.selectedSegmentIndex {
      case 1:
          self.view.backgroundColor = UIColor.greenColor()
          println("Green")
      case 2:
          self.view.backgroundColor = UIColor.blueColor()
          println("Blue")
      default:
          self.view.backgroundColor = UIColor.purpleColor()
          println("Purple")
      }
  }

  override func viewDidLoad() {
      super.viewDidLoad()
      // 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.
  }
}

SOURCE: http://www.richardhsu.me/

U can do like this...

UISegmentedControl *segmentControl = [[UISegmentedControl alloc]initWithItems:@[@"One",@"Two"]];

[segmentControl setSegmentedControlStyle:UISegmentedControlStyleBar];
segmentControl.frame = CGRectMake(10, 50, 300, 30);
[segmentControl addTarget:self action:@selector(segmentedControlValueDidChange:) forControlEvents:UIControlEventValueChanged];
[segmentControl setSelectedSegmentIndex:0];
[scrollView addSubview:segmentControl];
[segmentControl release];

Step 2:

-(void)segmentedControlValueDidChange:(UISegmentedControl *)segment
{
switch (segment.selectedSegmentIndex) {
    case 0:{
        //action for the first button (Current)
        break;}
    case 1:{
        //action for the first button (Current)
        break;}
    }
}

Updated answer for Swift 4.x:

class SegmentClass: UIViewController {
    func addControl()  {
        let items = ["Uno", "Dos", "Tres"]
        let segmentedControl = UISegmentedControl(items: items)
        segmentedControl.frame = CGRect(x: 35, y: 200, width: 250, height: 50)
        segmentedControl.addTarget(self, action: #selector(segmentAction(_:)), for: .valueChanged)
        segmentedControl.selectedSegmentIndex = 1
        view.addSubview(segmentedControl)
    }

    @objc func segmentAction(_ segmentedControl: UISegmentedControl) {
        switch (segmentedControl.selectedSegmentIndex) {
        case 0:
            break // Uno
        case 1:
            break // Dos
        case 2:
            break // Tres
        default:
            break
        }
    }
}

Original answer in Objective-C:

NSArray *itemArray = [NSArray arrayWithObjects: @"Uno", @"Dos", @"Tres", nil];
UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:itemArray];
segmentedControl.frame = CGRectMake(35, 200, 250, 50);
[segmentedControl addTarget:self action:@selector(segmentAction:) forControlEvents: UIControlEventValueChanged];
segmentedControl.selectedSegmentIndex = 1;
[self.view addSubview:segmentedControl];

1. Create an array to store the values for the segment
2. Initialize the segment using the array
3. Assign it a location on the screen & size the control
4. Point it towards a method that is called when the user interacts with it
5. Select a default value (in this case, Dos)
6. Place it on the main view

Then create the segmentAction method that is called when the user changes a value

- (void)segmentAction:(UISegmentedControl *)segment
{
    switch (segment.selectedSegmentIndex) {
        case 0:
            // Uno
            break;
        case 1:
            // Dos
            break;
        case 2:
            // Tres
            break;
        default:
            break;
    }
}

I just prefer the switch statement because it is cleaner to look at. You can improve it by creating an enum and using the values in it for the options (optionUno,optionDos,optionTres) instead of 0,1,2.

Step 1. Create segment control with index values

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"common-bg.jpg"]];
    [self.navigationItem setHidesBackButton:YES];

    //-- For creating segment control in navigation bar
     UISegmentedControl *mainSegment = [[UISegmentedControl alloc] initWithItems:[NSArray arrayWithObjects:@"Back", @"Month", @"Year", @"Home", nil]];
    [mainSegment setSegmentedControlStyle:UISegmentedControlStyleBar];
    mainSegment.frame = CGRectMake(0,0, 400, 43);
    self.navigationItem.titleView = mainSegment;
    mainSegment.selectedSegmentIndex = 1;
    [mainSegment addTarget:self action:@selector(mainSegmentControl:) forControlEvents: UIControlEventValueChanged];
    [self.view addSubview:mainSegment];
    //--**--

}

Step 2. Create subview

- (void)mainSegmentControl:(UISegmentedControl *)segment
{

    if(segment.selectedSegmentIndex == 0)
    {
        // action for the first button (Current or Default)
    }
    else if(segment.selectedSegmentIndex == 1)
    {
        // action for the second button 
    }
    else if(segment.selectedSegmentIndex == 2)
    {
        // action for the third button 
    } 
    else if(segment.selectedSegmentIndex == 3)
    {
        // action for the fourth button 
    }
}