code snippet for blog Develop For watchOS 2 2: New UI Elements - Picker

InterfaceController.m

//
//  InterfaceController.m
//  WatchPicker Extension
//
//  Created by Peng on 6/15/15.
//  Copyright © 2015 Peng. All rights reserved.
//

#import "InterfaceController.h"


@interface InterfaceController()
@property (weak, nonatomic) IBOutlet WKInterfacePicker *picker;
@property (weak, nonatomic) IBOutlet WKInterfaceLabel *label;

@property (strong, nonatomic) NSArray <WKPickerItem *> *pickerItems;
@property (strong, nonatomic) WKPickerItem *selectedItem;

@end


@implementation InterfaceController

- (void)awakeWithContext:(id)context {
    [super awakeWithContext:context];

    // Configure interface objects here.
}

- (void)willActivate {
    // This method is called when watch view controller is about to be visible to user
    [super willActivate];
    
    WKPickerItem *iOS = [[WKPickerItem alloc] init];
    iOS.title = @"iOS";
    
    WKPickerItem *macOSX = [[WKPickerItem alloc] init];
    macOSX.title = @"Mac OS X";
    
    WKPickerItem *watchOS = [[WKPickerItem alloc] init];
    watchOS.title = @"watchOS";
    
    _pickerItems = @[iOS, macOSX, watchOS];
    [_picker setItems:self.pickerItems];

}
- (IBAction)pickerSelected:(NSInteger)value {
    
    WKPickerItem *selectedItem = self.pickerItems[value];
    
    [self.label setText:selectedItem.title];
}

- (void)didDeactivate {
    // This method is called when watch view controller is no longer visible
    [super didDeactivate];
}

@end