(Swift)

import UIKitclass ViewController: UIViewController, UIPickerViewDataSource {    var picker: UIPickerView!        override func viewDidLoad() {        super.viewDidLoad()                picker = UIPickerView()                // select the current view controller as the data source of the picker view        picker.dataSource = self        picker!.delegate = self                picker.center = view.center        view.addSubview(picker)    }        /*        Implemented some of the methods of the UIPickerViewDataSource protocol    */        // returns the number of 'columns' to display    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {        if pickerView == picker {            return 1        }        return 0    }        // returns the number of rows in each component    func pickerView(pickerView: UIPickerView,        numberOfRowsInComponent component: Int) -> Int {        if pickerView == picker {            return 10        }        return 0    }}func pickerView(pickerView: UIPickerView,    titleForRow row: Int,    forComponent component: Int) -> String! {    return "\(row + 1)"}

 

(Objective-C)

@interface ViewController () 
     
      @property (nonatomic, strong) UIPickerView *myPicker;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];        self.myPicker = [[UIPickerView alloc] init];        // select the current view controller as the data source of the picker view    self.myPicker.dataSource = self;    self.myPicker.delegate = self;        self.myPicker.center = self.view.center;    [self.view addSubview:self.myPicker];}/*    Implemented some of the methods of the UIPickerViewDataSource protocol*/- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {    if ([pickerView isEqual:self.myPicker]){        return 1;    }    return 0;}- (NSInteger) pickerView:(UIPickerView *)pickerView    numberOfRowsInComponent:(NSInteger)component {    if ([pickerView isEqual:self.myPicker]){        return 10;    }    return 0;}- (NSString *)pickerView:(UIPickerView *)pickerView    titleForRow:(NSInteger)row    forComponent:(NSInteger)component {    if ([pickerView isEqual:self.myPicker]) {        /* Row is zero-based and we want the first row (with index 0)        to be rendered as Row 1, so we have to +1 every row index */                return [NSString stringWithFormat:@"Row %ld", (long)row + 1];    }        return nil;}