Question

I got a Problem with a Picker View in Xcode 4.4. I want to populate 1 Picker with multiple arrays. I watched / read a lot of tutorials and could get almost to work. This is my code:

*.h

 #import <UIKit/UIKit.h>

@interface PickerView : UIViewController

<UIPickerViewDataSource,UIPickerViewDelegate>
{
    IBOutlet UIPickerView *picker;

    NSMutableArray *array_1;
    NSMutableArray *array_2;
}

@property (strong, nonatomic) IBOutlet UIView *pickerContainer;
@property (strong, nonatomic) IBOutlet UITextField *textfield_1;
@property (strong, nonatomic) IBOutlet UITextField *textfield_2;

- (IBAction)showArray_1Picker:(id)sender;
- (IBAction)showArray_2Picker:(id)sender;
- (IBAction)hidePicker:(id)sender;

@end

*.m

#import "PickerView.h"

@interface PickerView ()

@end

@implementation PickerView
@synthesize pickerContainer;
@synthesize textfield_1;
@synthesize textfield_2;

int textFieldTouched = 0;

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)picker
{
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent (NSInteger)component
{
    switch(textFieldTouched)
    {
        case 1:
            return [array_1 count];
            break;
        case 2:
            return [array_2 count];
            break;
        default:
            return 0;
    }
}


- (NSString *)pickerView:(UIPickerView *)picker titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    switch(textFieldTouched)
    {
        case 1:
            return [array_1 objectAtIndex:row];
            break;
        case 2:
            return [array_2 objectAtIndex:row];
            break;
        default:
            return @"nothing";
    }
}

- (void) pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    switch(textFieldTouched)
    {
        case 1:
            textfield_1.text = [array_1 objectAtIndex:[pickerView selectedRowInComponent:0]];
            break;
        case 2:
            textfield_2.text = [array_2 objectAtIndex:[pickerView selectedRowInComponent:0]];
            break;
    }
}

 - (void)viewDidLoad
 {
    array_1 = [[NSMutableArray alloc] init];
    [array_1 addObject:@"1"];
    [array_1 addObject:@"2"];
    [array_1 addObject:@"3"];
    [array_1 addObject:@"4"];
    [array_1 addObject:@"5"];

    array_2 = [[NSMutableArray alloc] init];
    [array_2 addObject:@"a"];
    [array_2 addObject:@"b"];
    [array_2 addObject:@"c"];
    [array_2 addObject:@"d"];
    [array_2 addObject:@"e"];

    pickerContainer.frame = CGRectMake(0, 460, 320, 261);

    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [self setPickerContainer:nil];
    [self setTextfield_1:nil];
    [self setTextfield_2:nil];
    [super viewDidUnload];
}

- (IBAction)showArray_1Picker:(id)sender
{
    [textfield_1 resignFirstResponder];
    textFieldTouched = 1;
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];
    pickerContainer.frame = CGRectMake(0, 200, 320, 261);
    [UIView commitAnimations];
}

- (IBAction)showArray_2Picker:(id)sender
{
    [textfield_2 resignFirstResponder];
    textFieldTouched = 2;
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];
    pickerContainer.frame = CGRectMake(0, 200, 320, 261);
    [UIView commitAnimations];
}

- (IBAction)hidePicker:(id)sender
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];
    pickerContainer.frame = CGRectMake(0, 460, 320, 261);
    [UIView commitAnimations];
}

@end

So i got 2 main problems:

1. If i set textFieldTouched = 0 (or > 2) like i did before my picker is empty when it shows up. Anyway if I hide it again it writes the first value of the corresponding array in the textfield.

2. If i set textFieldTouched = 1 or =2 the picker is populated with the related array no matter what text field I try to edit. But if I scroll the values on the picker out of my sight they have changed when i scroll back.

I want to have it like this:

If i touch text field 1 the picker shows up populated with array 1

If i touch text field 2 the picker shows up populated with array 2

ans so on.

Can u help me with that?

I’ve uploaded the code so you can look at it better.

https://dl.dropbox.com/u/5858884/ProblemCode.zip

P.S.

English is not my mother language so please excuse mistakes 😉

I started programming 2 weeks ago, so if u find something wrong in my code that doesnt belong to my problem please tell me so I can get better 🙂

Answer 1

In your showArray1Picker and showArray2Picker methods add the line:

[picker reloadAllComponents];

This will cause the picker to reload its data. You also need to connect the IBOutlet, picker, to the picker view in IB — I noticed that it was not connected.