Pickers consist of a rotating scrollable view, which is used for picking a value from the list of items.
- (void)reloadAllComponents - (void)reloadComponent:(NSInteger)component - (NSInteger)selectedRowInComponent:(NSInteger)component - (void)selectRow:(NSInteger)row inComponent:(NSInteger)component animated:(BOOL)animated
We will add instances for a text field, a picker view, and an array. We will adopt UITextFieldDelegate, UIPickerViewDataSource and UIPickerViewDelegate protocols. The ViewController.h is as follows −
#import <UIKit/UIKit.h> @interface ViewController : UIViewController <UITextFieldDelegate, UIPickerViewDataSource, UIPickerViewDelegate> { UITextField *myTextField; UIPickerView *myPickerView; NSArray *pickerArray; } @end
-(void)addPickerView { pickerArray = [[NSArray alloc]initWithObjects:@"Chess", @"Cricket",@"Football",@"Tennis",@"Volleyball", nil]; myTextField = [[UITextField alloc]initWithFrame: CGRectMake(10, 100, 300, 30)]; myTextField.borderStyle = UITextBorderStyleRoundedRect; myTextField.textAlignment = UITextAlignmentCenter; myTextField.delegate = self; [self.view addSubview:myTextField]; [myTextField setPlaceholder:@"Pick a Sport"]; myPickerView = [[UIPickerView alloc]init]; myPickerView.dataSource = self; myPickerView.delegate = self; myPickerView.showsSelectionIndicator = YES; UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStyleDone target:self action:@selector(done:)]; UIToolbar *toolBar = [[UIToolbar alloc]initWithFrame: CGRectMake(0, self.view.frame.size.height- myDatePicker.frame.size.height-50, 320, 50)]; [toolBar setBarStyle:UIBarStyleBlackOpaque]; NSArray *toolbarItems = [NSArray arrayWithObjects: doneButton, nil]; [toolBar setItems:toolbarItems]; myTextField.inputView = myPickerView; myTextField.inputAccessoryView = toolBar; }
Implement the delegates as shown below −
#pragma mark - Text field delegates -(void)textFieldDidBeginEditing:(UITextField *)textField { if ([textField.text isEqualToString:@""]) { [self dateChanged:nil]; } } #pragma mark - Picker View Data source -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 1; } -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { return [pickerArray count]; } #pragma mark- Picker View Delegate -(void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component { [myTextField setText:[pickerArray objectAtIndex:row]]; } - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow: (NSInteger)row forComponent:(NSInteger)component { return [pickerArray objectAtIndex:row]; }
Update viewDidLoad in ViewController.m as follows −
(void)viewDidLoad { [super viewDidLoad]; [self addPickerView]; }
When we run the application, we'll get the following output −
On selecting the text field, the picker view will be displayed as shown below where we can select our choice −