IOS 7 Study - UISegmentedControl

You would like to present a few options to your users from which they can pick an
option, through a UI that is compact, simple, and easy to understand.

 

effect:

 

 1. declare control

#import "ViewController.h"



@interface ViewController ()



@property (nonatomic, strong) UISegmentedControl *mySegmentedControl;



@end



@implementation ViewController

 

 2. create the segmented control in the viewDidLoad method of your view controller

- (void)viewDidLoad {

  [super viewDidLoad];



  NSArray *segments = [[NSArray alloc] initWithObjects:

        @"iPhone",

        @"iPad",

        @"iPod",

        @"iMac", nil];



  self.mySegmentedControl = [[UISegmentedControl alloc]

                                            initWithItems:segments];

  self.mySegmentedControl.center = self.view.center;

  [self.view addSubview:self.mySegmentedControl];
}

3. use the addTarget:action:forControlEvents: method of the segmented control to

　　recognize when the user selects a new option

   // add event listener
  [self.mySegmentedControl addTarget:self
      action:@selector(segmentChanged:)
      forControlEvents:UIControlEventValueChanged];

 

- (void)viewDidLoad {

  [super viewDidLoad];



  NSArray *segments = @[

    @"iPhone",

    @"iPad",

    @"iPod",

    @"iMac"

  ];

  

  self.mySegmentedControl = [[UISegmentedControl alloc]

                              initWithItems:segments];



  self.mySegmentedControl.center = self.view.center;



  [self.view addSubview:self.mySegmentedControl];



  [self.mySegmentedControl addTarget:self

         action:@selector(segmentChanged:)

         forControlEvents:UIControlEventValueChanged];

}

 

4. segment change event

- (void) segmentChanged:(UISegmentedControl *)paramSender {

  if ([paramSender isEqual:self.mySegmentedControl]) {

    NSInteger selectedSegmentIndex = [paramSender   selectedSegmentIndex];


    NSString *selectedSegmentText =

       [paramSender titleForSegmentAtIndex:selectedSegmentIndex];



    NSLog(@"Segment %ld with %@ text is selected",

             (long)selectedSegmentIndex,

              selectedSegmentText);

  }

}

 

result on console:

Segment 0 with iPhone text is selected
Segment 1 with iPad text is selected
Segment 2 with iPod text is selected
Segment 3 with iMac text is selected

 

If no item is selected, this method returns the value –1