Ejemplo programático UIPickerView?

Question

¿Cómo configuro programáticamente UIPickerView en una vista sin usar el Generador de interfaz? También tiene problemas para entender cómo trabajar con las porciones delegadas de UIPickerView.

Answer 1

Para añadir UIPickerView programación:

- (void)pickerView:(UIPickerView *)pV didSelectRow:(NSInteger)row inComponent:(NSInteger)component 
{ 
    if(component == 1) 
     selectedRowPicker1 = row; 
    else if(component == 2) 
     selectedRowPicker2 = row; 
    else 
     selectedRowPicker3 = row; 
} 

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView 
{ 
    return 3; 
} 

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component 
{ 
    if(component == 1) 
     return [list1 count]; 
    else if(component == 2) 
     return [list2 count]; 
    else 
     return [list3 count]; 
} 

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component 
{ 
    if(component == 1) 
     val1 = [list1 objectAtIndex:row]; 
    else if(component == 2) 
     val2 = [list2 objectAtIndex:row]; 
    else 
     val3 = [list3 objectAtIndex:row]; 

    return strTemp; 
} 

Answer 2

Esto no funcionará en iOS 8

Crear UIPickerView programación con DataSource

archivo .h

@interface PickerViewTestAppViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource> { 
    UIActionSheet *pickerViewPopup; 
    UIPickerView *categoryPickerView; 
    UIPickerView *pickerView; 
    NSMutableArray *dataArray; 
} 

@property (nonatomic, retain) UIActionSheet *pickerViewPopup; 
@property (nonatomic, retain) UIPickerView *categoryPickerView; 
@property (nonatomic, retain) NSMutableArray *dataArray; 

@end 

archivo .m

@implementation PickerViewTestAppViewController 

@synthesize pickerViewPopup,categoryPickerView; 
@synthesize dataArray; 

- (void)viewDidLoad { 
    [super viewDidLoad]; 

// Init the data array. 
dataArray = [[NSMutableArray alloc] init]; 

// Add some data for demo purposes. 
[dataArray addObject:@"One"]; 
[dataArray addObject:@"Two"]; 
[dataArray addObject:@"Three"]; 
[dataArray addObject:@"Four"]; 
[dataArray addObject:@"Five"]; 

pickerViewPopup = [[UIActionSheet alloc] initWithTitle:nil delegate:self cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil]; 

categoryPickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 44, 0, 0)]; 

[categoryPickerView setDataSource: self]; 
[categoryPickerView setDelegate: self]; 
categoryPickerView.showsSelectionIndicator = YES; 

    UIToolbar *pickerToolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)]; 
    pickerToolbar.barStyle = UIBarStyleBlackOpaque; 
    [pickerToolbar sizeToFit]; 

    UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil]; 

    UIBarButtonItem *doneBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(categoryDoneButtonPressed)]; 

    UIBarButtonItem *cancelBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(categoryCancelButtonPressed)]; 

    [pickerToolbar setItems:@[cancelBtn, flexSpace, doneBtn] animated:YES]; 

    [pickerViewPopup addSubview:pickerToolbar]; 
    [pickerViewPopup addSubview:categoryPickerView]; 
    [pickerViewPopup showInView:self.view]; 
    [pickerViewPopup setBounds:CGRectMake(0,0,320, 464)]; 
} 

- (void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component { 
// Handle the selection 

NSLog(@"%@",[dataArray objectAtIndex:row]);  
selectedCategory = [NSString stringWithFormat:@"%@",[dataArray objectAtIndex:row]]; 
} 
// tell the picker how many rows are available for a given component 
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { 
    return [dataArray count]; 
} 

// tell the picker how many components it will have 
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { 
    return 1; 
} 

// tell the picker the title for a given component 
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { 

    return [dataArray objectAtIndex: row]; 

} 

// tell the picker the width of each row for a given component 
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component { 
    int sectionWidth = 300; 

    return sectionWidth; 
} 

-(void)categoryDoneButtonPressed{ 
categoryLable.text = selectedCategory; 
[pickerViewPopup dismissWithClickedButtonIndex:1 animated:YES]; 
} 

-(void)categoryCancelButtonPressed{ 
    [pickerViewPopup dismissWithClickedButtonIndex:1 animated:YES]; 
} 

Ref: http://gabriel-tips.blogspot.in/2011/04/uipickerview-add-it-programmatically_04.html

Answer 3

NSInteger selectCourse=[_coursePicker selectedRowInComponent:0]; 
    NSInteger selectSem=[_coursePicker selectedRowInComponent:1]; 
    NSString *whatCourse=[Course objectAtIndex:selectCourse]; 
    NSString *whatSem=[Sem objectAtIndex:selectSem]; 

    NSString *courses=[[NSString alloc]initWithFormat:@"Course : %@ - %@",whatCourse,whatSem]; 

    [self.selectedCours setTitle:courses forState:UIControlStateNormal];