I have a xib in which I have added a UIViewController named delta. The view under delta is controlled by the delta viewcontroller, not the file owner. On the delta view, I have a UIViewPicker. My issue is that I am programming in the UIPickerView in the deltaviewcontroller and I'm issuing deltaviewcontroller as the delegate and data source for the UIPickerView. Everything should work, but when I load the deltaviewcontroller's view, the application crashes. If I carry out everything the same way under the file's owner view, it works fine. I'm wondering if there is really a way to make the UIPickerView work with a UIViewController and no necessarily a file's owner.
For references, the code:
Header
#interface DeltaViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource> {
NSMutableArray *arrayNo;
IBOutlet UIPickerView *pickerView;
}
#property (nonatomic, retain) UIPickerView *pickerView;
#property (nonatomic, retain) NSMutableArray *arrayNo;
#end
Implementation
#import "DeltaViewController.h"
#implementation DeltaViewController
#synthesize pickerView;
#synthesize arrayNo;
- (void)viewDidLoad
{
NSMutableArray *dollarsArray = [[NSMutableArray alloc] init];
for (int i = 0; i < 100; i++)
{
NSString *item = [[NSString alloc] initWithFormat:#"%i", i];
[dollarsArray addObject:item];
}
self.arrayNo = dollarsArray;
[dollarsArray release];
}
#pragma mark -
#pragma mark Picker Data Source Methods
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return [arrayNo count];
}
#pragma mark Picker Delegate Methods
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
return [arrayNo objectAtIndex:row];
}
- (void)dealloc {
[arrayNo release];
[pickerView release];
[super dealloc];
}
#end
Please point out if I'm doing anything wrong. Help is much appreciated.
If you search how to add a UIPickerView in a UIView, just check out the Apple sample code for UIPickerView. I think it's one of the best ways learning to use the different classes correctly. There are five project which includes an UIPickerView. Here's the link
UIPickerView class reference and sample code
Try doing
[self.view addSubview:pickerView];
in your viewDidLoad method.
Related
Ok I am trying to connect a UIPickerView with a custom class. The idea is to have 3 picker views in one normal view.
So far I have created one view and bound it to my class TestView.h
Then I added a picker view to the view in the storyboard (iOS 5)
I then created a class for this picker view:
#interface TestPickerView : UIPickerView <UIPickerViewDelegate, UIPickerViewDataSource>
{
NSArray *data;
}
Then tried to add a Property to my normal view (TestView.h)
#import "TestPickerView.h"
#interface TestView : UIViewController
#property (strong, nonatomic) IBOutlet TestPickerView *myTestPicker;
#end
But how do i bind the UIPickerView inside my normal view to this class/property?
I will in the end have 3 UIPickerView's and my idea was to have 3 references in my UIViewController to control these UIPickerViews. That way I could set the data (datasource) using the properties once when the normal view is loading and then the PickerViews would just show. Hopefully i would also be able to get notified in my normal view when the value in one of the views occur.
Please call your TestView >> TestViewController instead, as it is a controller.
In your storyboard, select the PickerView and change it's class name to TestPickerView.
After that just create your three IBOutlets and connect the PickerViews. That's it.
// edit: To explain, how you distinguish between the pickers. Make 3 outlets, e.g.:
IBOutlet TestPickerView *picker1;
IBOutlet TestPickerView *picker2;
IBOutlet TestPickerView *picker3;
And than in your delegate method, check which picker did call the delegate, e.g.:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
if(pickerView == self.picker1)
{
// picker1
}
else if(pickerView == self.picker2)
{
// picker2
}
else
{
// picker3
}
}
Here you go dude, this is how I did it on several of my apps and games.
#import <UIKit/UIKit.h>
#pragma mark - Delegate Protocol
#protocol someDelegate
#required
-(void)somePickerFinishedPicking:(id)item;
#end
#pragma mark - Class interface
#interface SomePicker : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource>
{
NSMutableArray* dataSource;
}
#pragma mark - Property Istantiation
#property (nonatomic, retain) NSMutableArray* dataSource;
#property (nonatomic, retain) id <someDelegate> pickDelegate;
#pragma mark - Constructors / Destructors
- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil;
- (void) didReceiveMemoryWarning;
- (void) dealloc;
- (void) createDataSource;
#pragma mark - View Lifecycle
- (void) viewDidLoad;
#pragma mark - UIPicker Protocols
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;
-(UIView*) pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view;
#pragma mark - Delegate Protocols
-(void) handlePickerDidFinish:(id)item;
#end
this for your .m
#pragma mark - Class Implementation
#implementation SomePicker
#pragma mark - Variable synthesize
// ARRAYS
#synthesize dataSource;
// DELEGATES
#synthesize pickDelegate = _pickDelegate;
#pragma mark - Constructors / Deconstructors
// Class initialization
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil;
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
dataSource = [[NSMutableArray alloc] init];
[self createDataSource];
}
return self;
}
// Handles memory warning events
- (void)didReceiveMemoryWarning
{
// Release the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
// Garbage Collection
- (void) dealloc;
{
// Release what you need
self.dataSource = nil;
[super dealloc];
}
// Creates the occasion entries for the picker
-(void)createDataSource
{
NSMutableDictionary* dataDictionary = [[NSMutableDictionary alloc] init];
// create your data source here or just forget about this and pass it from the parentViewController.
[dataDictionary release];
}
#pragma mark - View lifecycle
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad;
{
[super viewDidLoad];
UIPickerView* occasionsPicker = [[UIPickerView alloc] init];
[occasionsPicker setDataSource:self];
[occasionsPicker setDelegate:self];
[occasionsPicker setTag:888];
[occasionsPicker selectRow:500 inComponent:0 animated:YES];
[self.view addSubview:occasionsPicker];
[occasionsPicker release];
[self handlePickerDidFinish:[[self.dataSource objectAtIndex:(500 % self.dataSource.count)] objectForKey:#"key"]];
}
#pragma mark - UIPicker Protocols
// Creates the rows in the picker.
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
// Endless roll illusion else just bind it to the size of the data source
return 1000;
}
// Determines the number of columns in the picker
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
// Add however many columns you need
return 1;
}
// Handles the event when the user picks a row.
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
//this does something with the row selected
[self handlePickerDidFinish:[[self.dataSource objectAtIndex:(row % self.dataSource.count)] objectForKey:#"key"]];
}
// Creates the custom view for each cell so the text shows in accordance to the App Style
-(UIView*) pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
UILabel* customRowLabel = [[[UILabel alloc] initWithFrame:CGRectMake(0, 0, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)] autorelease];
customRowLabel.font = [UIFont fontWithName:#"HelveticaNeue" size: 16];
customRowLabel.textColor = [UIColor colorWithRed:kColorRed green:kColorGreen blue:kColorBlue alpha:1];
customRowLabel.textAlignment = UITextAlignmentCenter;
customRowLabel.backgroundColor = [UIColor clearColor];
customRowLabel.text = [[self.dataSource objectAtIndex:(row % self.dataSource.count)] objectForKey:#"key"];
return customRowLabel;
}
#pragma mark - Delegate Protocols
// Notifies Delegate class that an action has been perfomed and passes the Mood String selected
-(void)handlePickerDidFinish:(id)item
{
[self.pickDelegate somePickerFinishedPicking:item];
}
#end
And just instantiate it like so on your parent ViewController:
CGRect rectPicker = CGRectMake(60, 100, 200, 216);
self.somePicker = [[[SomePicker alloc] init] autorelease];
[self.somePicker setPickDelegate:self];
[self.somePicker.view setBackgroundColor:[UIColor clearColor]];
self.somePicker.view.frame = rectPicker;
[self.somePicker.view setTag:777];
[self.somePicker.view setAlpha:0];
[self.view addSubview:self.somePicker.view];
~/End of Line
I have a plist (array of dictionaries) which populates a table view and works properly. I use Xcode 4 with storyboards.
Now I've created a detail view from a regular UIViewController and of course I want the selected name to be displayed in the nameLabel in the detail view. But I can't make the right connection. This is my code so far:
WineObject.m:
#import "WineObject.h"
#implementation WineObject
#synthesize libraryContent, libraryPlist;
- (id)initWithLibraryName:(NSString *)libraryName {
if (self = [super init]) {
libraryPlist = libraryName;
libraryContent = [[NSArray alloc] initWithContentsOfFile:[[NSBundle mainBundle]
pathForResource:libraryPlist ofType:#"plist"]];
}
return self;
}
- (NSDictionary *)libraryItemAtIndex:(int)index {
return (libraryContent != nil && [libraryContent count] > 0 && index < [libraryContent count])
? [libraryContent objectAtIndex:index]
: nil;
}
- (int)libraryCount {
return (libraryContent != nil) ? [libraryContent count] : 0;
}
- (void) dealloc {
if (libraryContent) [libraryContent release];
[super dealloc];
}
#end
ViewController.h:
#import <UIKit/UIKit.h>
#class WineObject;
#interface WinesViewController : UITableViewController {
WineObject *wine;
}
#end
ViewController.m:
#import "WinesViewController.h"
#import "WineObject.h"
#import "WineCell.h"
#interface WinesViewController ()
#end
#implementation WinesViewController
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (void)viewWillAppear:(BOOL)animated {
wine = [[WineObject alloc] initWithLibraryName:#"Wine"];
self.title = #"Vinene";
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [wine libraryCount];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"wineCell";
WineCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
cell.nameLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Name"];
cell.districtLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:#"District"];
cell.countryLabel.text = [[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Country"];
cell.bottleImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Image"]];
cell.flagImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Flag"]];
cell.fyldeImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Fylde"]];
cell.friskhetImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Friskhet"]];
cell.garvesyreImageView.image = [UIImage imageNamed:[[wine libraryItemAtIndex:indexPath.row] valueForKey:#"Garvesyre"]];
return cell;
}
#pragma mark - Table view delegate
#end
WineCell.h:
#import <UIKit/UIKit.h>
#interface WineCell : UITableViewCell
#property (nonatomic, strong) IBOutlet UILabel *nameLabel;
#property (nonatomic, strong) IBOutlet UILabel *districtLabel;
#property (nonatomic, strong) IBOutlet UILabel *countryLabel;
#property (nonatomic, strong) IBOutlet UIImageView *bottleImageView;
#property (nonatomic, strong) IBOutlet UIImageView *flagImageView;
#property (nonatomic, strong) IBOutlet UIImageView *fyldeImageView;
#property (nonatomic, strong) IBOutlet UIImageView *friskhetImageView;
#property (nonatomic, strong) IBOutlet UIImageView *garvesyreImageView;
#end
Are you using a XIB for interface or generating it programmatically?
If you are using a XIB, the issue is that you aren't loading it up:
Change
winesDetailViewController = [[WinesDetailViewController alloc] init];
To
winesDetailViewController = [[WinesDetailViewController alloc] initWithNibName:#"YourNibNameHere" bundle:nil];
Or, if you are generating it programmatically, you must first set nameLabel or it will be nil. #synthesize doesn't set the variable, it simply generates getters and setters so that you can set it from outside.
Inside your viewDidAppear: (or better yet inside your init) add:
self.nameLabel=[[UILabel alloc] initWithFrame:CGRectMake(100,100,100,100)];
EDIT: If you are using Storyboards, it appears that you have to do the following.
Storyboards are all about relationships. Inside the story board editor, you add buttons and tell them which view controller they connect to. The same idea applies to TableView Cells. You can add a prototype table view cell (and customize it) and assign a relationship to it. The relationship you will want to give it is your detail view.
1.) Subclass UITableViewCell and give it a property that is the dictionary that you are trying to send to the detail view
2.) When creating cells (cellForRowAtIndexPath:) you will need to make sure to dequeue your custom cell and assign your dictionary to the property that you gave it.
3.) Make sure that your detail view has the identifier: DetailView
4.) Inside the table view controller, add the following code:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"DetailView"])
{
//This works because by the time prepareForSeque: is called, the navigationController has loaded the new view
((DetailView *)[[self.navigationController viewControllers] objectAtIndex:0]).dataProperty=((MyCustomTableViewCell *)sender).dataProperty;
}
}
That ought to do it!
I have two view controllers. The CardWallet View Controller is my table view. Then the AddCard View Controller is where I input values for a new instance of an object named Card. So far, I am adding those Card instances in an array named myWallet which is in my CardWallet View Controller using a delegate and it works.
What I want is, after clicking the button in my AddCard View Controller, a new table cell will appear in my Card Wallet View, with the name depending on the recently added instance of Card. Below is my code, kindly check why is it that when I'm finished adding a new instance of Card, nothing appears in my table. I've done some research and went through some tutorials, this one is good, http://kurrytran.blogspot.com/2011/10/ios-5-storyboard-and.html, it helped me a lot regarding table view controllers. However, the tutorial doesn't cater my main concern for it's table's values only come from an array with static values.
Thanks!
CardWalletViewController.h
#import <UIKit/UIKit.h>
#interface CardWalletViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
}
#property (nonatomic, strong) NSMutableArray *myWallet;
-(void) printArrayContents;
#end
CardWalletViewController.m
#import "CardWalletViewController.h"
#import "AddCardViewController.h"
#import "Card.h"
#interface CardWalletViewController () <AddCardDelegate>
#end
#implementation CardWalletViewController
#synthesize myWallet = _myWallet;
- (NSMutableArray *) myWallet
{
if (_myWallet == nil) _myWallet = [[NSMutableArray alloc] init];
return _myWallet;
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([segue.identifier isEqualToString:#"showAddCardVC"]) {
AddCardViewController *addCardVC = (AddCardViewController *)segue.destinationViewController;
addCardVC.delegate = self;
}
}
- (void)printArrayContents
{
// I want to show the name of each instance of card
for ( int i = 0; i < self.myWallet.count; i++) {
Card *cardDummy = [self.myWallet objectAtIndex:i];
NSLog(#"Element %i is %#", i,cardDummy.name );
}
}
- (void)addCardViewController:(AddCardViewController *)sender didCreateCard:(Card *)newCard
{
// insert a new card to the array
[self.myWallet addObject:newCard];
[self printArrayContents];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
// Release any retained subviews of the main view.
}
- (void)viewWillAppear:(BOOL)animated
{
}
- (void)viewWillDisappear:(BOOL)animated
{
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
//this method will return the number of rows to be shown
return self.myWallet.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell...
//---------- CELL BACKGROUND IMAGE -----------------------------
UIImageView *imageView = [[UIImageView alloc] initWithFrame:cell.frame];
UIImage *image = [UIImage imageNamed:#"LightGrey.png"];
imageView.image = image;
cell.backgroundView = imageView;
[[cell textLabel] setBackgroundColor:[UIColor clearColor]];
[[cell detailTextLabel] setBackgroundColor:[UIColor clearColor]];
//this will show the name of the card instances stored in the array
//
for ( int i = 0; i < self.myWallet.count; i++) {
Card *cardDummy = [self.myWallet objectAtIndex:i];
cell.textLabel.text = cardDummy.name;
}
//Arrow
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
#end
AddCardViewController.h
#import <UIKit/UIKit.h>
#import "Card.h"
#class AddCardViewController;
#protocol AddCardDelegate <NSObject>
- (void)addCardViewController:(AddCardViewController *)sender
didCreateCard:(Card *) newCard;
#end
#interface AddCardViewController : UIViewController <UITextFieldDelegate>
#property (strong, nonatomic) IBOutlet UITextField *cardNameTextField;
#property (strong, nonatomic) IBOutlet UITextField *pinTextField;
#property (strong, nonatomic) IBOutlet UITextField *pointsTextField;
#property (nonatomic, strong) id <AddCardDelegate> delegate;
#end
AddCardViewController.m
#import "AddCardViewController.h"
#import "Card.h"
#import "CardWalletViewController.h"
#interface AddCardViewController ()
#end
#implementation AddCardViewController
#synthesize cardNameTextField = _cardNameTextField;
#synthesize pinTextField = _pinTextField;
#synthesize pointsTextField = _pointsTextField;
#synthesize delegate = _delegate;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.cardNameTextField becomeFirstResponder];
}
- (void) viewWillDisappear:(BOOL)animated
{
}
- (BOOL) textFieldShouldReturn:(UITextField *)textField{
if ([textField.text length]) {
[self.cardNameTextField resignFirstResponder];
[self.pinTextField resignFirstResponder];
[self.pointsTextField resignFirstResponder];
return YES;
}
else {
return NO;
}
}
- (void)viewDidLoad
{
self.cardNameTextField.delegate = self;
self.pinTextField.delegate = self;
self.pointsTextField.delegate = self;
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[self setCardNameTextField:nil];
[self setPinTextField:nil];
[self setPointsTextField:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (IBAction)addCard:(id)sender
{
Card *myNewCard = [[Card alloc] init];
myNewCard.name = self.cardNameTextField.text;
myNewCard.pin = self.pinTextField.text;
myNewCard.points = [self.pointsTextField.text intValue];
// to check if the text fields were filled up by the user
if ([self.cardNameTextField.text length] && [self.pinTextField.text length] && [self.pointsTextField.text length])
{
[[self presentingViewController] dismissModalViewControllerAnimated:YES];
NSLog(#"name saved %#", myNewCard.name);
NSLog(#"pin saved %#", myNewCard.pin);
NSLog(#"points saved %i", myNewCard.points);
[self.delegate addCardViewController:self didCreateCard:myNewCard];
// to check if there is a delegate
if (self.delegate){
NSLog(#"delegate is not nil");
}
}
}
#end
Card.h
#import <Foundation/Foundation.h>
#interface Card : NSObject
#property (nonatomic, strong) NSString *name;
#property (nonatomic, strong) NSString *pin;
#property (nonatomic) int points;
#end
Card.m
#import "Card.h"
#implementation Card
#synthesize name = _name;
#synthesize pin = _pin;
#synthesize points = _points;
#end
I should get the obvious question out of the way before anyone starts dwelling too deep into this - do you have some mechanism of reloading the data after you add a new card (e.g. call [tableView reloadData] from the CardWalletViewController)? I didn't see anything like that, and I've always used this whenever I add something new to a table.*
*If the table contains too much data, you may want to reload only a part of it.
Update 1: Class Inheritance
Every Objective C class has to inherit from some other class in the hierarchy. By default, unless you say otherwise, all of your custom classes will inherit from NSObject, which is the most generic object out there (equivalent of Object, if you've done Java programming). Changing the parent class is done by simply changing the class after the : in your interface declaration. So when you say
#interface CardWalletViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
what you are saying is "declare a CardWallerViewController custom class that inherits from UIViewController and implements the UITableViewDelegate and UITableViewDataSource protocols" (if you don't know what protocols are, ask).
Now, back to your question. Changing the parent class should be easy now - you just change that : UIViewController to : UITableViewController and you are done. After you do this, your CardWallerViewController (also, "Waller", really?) will behave like a UITableView, not like a generic UIView. When doing this, you will also not need to tell it to implement the delegate and dataSource protocols - UITableViewController does that by default.
As a final note, when you add new files to your Xcode project, you can tell the program which class you want to inherit from. It defaults to UIView for views, but that's simply because this is the most generic view class. As you begin to use more specific classes (UITableViewController, UIPickerViewController, UITableViewCell, to name a few), changing the parent class off the bat will prove to be more than helpful.
Update 2: UITableViewCells
That for-loop you've got going there is a (relatively) lot of work you don't need to do. Since your table corresponds directly to your myWallet property, this means that the cell in row N of your table will represent the card at index N of your array. You can use that to your advantage. In the tableView:cellForRowAtIndexPath: method, you tell the program what to do with the cell at the specific indexPath (which is really just section + row for that table). The trick is, this method instantiates the cells one at a time. So instead of doing the for-loop, you can just say (at the end)
cell.textLabel.text = [self.myWallet objectAtIndex:indextPath.row].name;
For any cell in row N, this will look at the Nth Card object inside myWallet and use its name to set the cell's textLabel.text. If it gives you problems, save [self.myWallet objectAtIndex:indextPath.row] in some tempCard object, and then do cell.textLabel.text = tempCard.name. This is also the proper way to populate cells in a tableView - you only care about one cell at a time, because that's how the method works anyway. Imagine if you had 1,000,000 Cards inside your array - doing the for-loop would force the program to go through the array 1,000,000 times for each cell. Say hello to a 1,000,000,000,000 operations :)
i think u can add the imageview as subview to cell
UIImageView *imageView = [[UIImageView alloc] initWithFrame:cell.frame];
UIImage *image = [UIImage imageNamed:#"LightGrey.png"];
imageView.image = image;
[cell addSubview:imageView];
[[cell textLabel] setBackgroundColor:[UIColor clearColor]];
[[cell detailTextLabel] setBackgroundColor:[UIColor clearColor]];
I'm new to iOS dev, so this is probably easy to fix. I have a custom view controller in which I'm adopting the protocols to control a UIPickerView in a nib. Everything works fine unless, in the iPad simulator, I scroll the picker beyond the first item in the list or the last item in the list and release. It kicks the following error:
Thread 1: Program received signal: "EXC_BAD_ACCESS"
on this line of my main.m class:
int retVal = UIApplicationMain(argc, argv, nil, nil);
Relevant code follows:
ViewController.h
#interface BirdColorViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource> {
IBOutlet UIPickerView *birdColorPicker;
NSArray *birdColors;
}
#property (nonatomic,retain) IBOutlet UIPickerView *birdColorPicker;
Viewcontroller.m
- (void)dealloc
{
[birdColorPicker release];
[super dealloc];
}
...
- (void)viewDidLoad
{
[super viewDidLoad];
birdColors = [NSArray arrayWithObjects:#"Blue",#"Yellow",#"Red",nil];
birdColorPicker.delegate = self;
birdColorPicker.dataSource = self;
}
...
#pragma mark - UIPickerViewDataSource methods
//(UIPickerView *)thePickerView
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return [birdColors count];
}
#pragma mark - UIPickerViewDelegate methods
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
return [birdColors objectAtIndex:row];
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
// Set value in prefs/model
}
Try:
birdColors = [[NSArray alloc] initWithObjects:#"Blue",#"Yellow",#"Red",nil];
instead of birdColors = [NSArray arrayWithObjects:#"Blue",#"Yellow",#"Red",nil];
Make birdColors a property also (nonatomic, retain) like you do with the pickerView.
Your array is not being retained, so you're accessing zombie memory.
Set NSZombieEnabled=YES in the properties/General panel of your Executable. That will tell you exactly what is being accessed.
I am using two UIPickers in a view.
first picker has 3 components and second has one.
but when I select items, it shows correct items from first picker but always return first item from second picker regardless of selected row.
Please help.
here is the code I am using.
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
if (pickerView == triplePicker)
return 3;
else {
return 1;
}
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
if (pickerView == triplePicker) {
if (component == kColorComponent)
return[colorList count];
if (component == kClarityComponent)
return[clarityList count];
return[shapeList count];
}
else{
return [listPickerItems count];
}
}
-(NSString *)pickerView:(UIPickerView *)pickerView
titleForRow:(NSInteger)row
forComponent:(NSInteger)component
{
if (pickerView == triplePicker) {
if (component == kColorComponent)
return [colorList objectAtIndex:row];
if (component == kClarityComponent)
return [clarityList objectAtIndex:row];
return [shapeList objectAtIndex:row];
}
else{
return [listPickerItems objectAtIndex:row];
}
}
in buttonpressed event I have following for second picker to return the item selected:
NSInteger pickrow = [listPicker selectedRowInComponent:0];
NSString *picked = [listPickerItems objectAtIndex:pickrow];
I would definitely suggest using two separate delegates to handle two pickers.
Aside from that, I'm going to guess that you're using Interface Builder to set up your view. If that's the case check if you have properly linked your listPicker with your File's Owner. If listPicker would be nil, then selectedRowInComponent: would always return null (0 for NSInteger), hence would always select the first item in your array.
EDIT: Some sample code for separate delegates:
You need to create a second class to be your delegate, like this:
FirstPickerDelegate.h
#import <Foundation/Foundation.h>
#class UntitledViewController;
#interface FirstPickerViewDelegate : NSObject <UIPickerViewDelegate, UIPickerViewDataSource> {
NSArray* values;
IBOutlet UntitledViewController* viewController;
}
-(void) loadData;
#property (nonatomic, retain) NSArray* values;
#property (nonatomic, assign) IBOutlet UntitledViewController* viewController;
#end
FirstPickerViewDelegate.m
#import "FirstPickerViewDelegate.h"
#implementation FirstPickerViewDelegate
#synthesize values;
#synthesize viewController;
-(id) init
{
if ( self = [super init] )
{
[self loadData];
}
return self;
}
-(void) loadData
{
NSArray* array = [[NSArray alloc] initWithObjects:#"first", #"second", #"third", nil];
self.values = array;
[array release];
}
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return [values count];
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
return [values objectAtIndex:row];
}
-(void) dealloc
{
self.values = nil;
[super dealloc];
}
#end
Your ViewController (UntitledViewController here, sorry about the name):
#import <UIKit/UIKit.h>
#class FirstPickerViewDelegate;
#interface UntitledViewController : UIViewController {
IBOutlet UIPickerView* firstPicker;
IBOutlet FirstPickerViewDelegate* firstDelegate;
}
#property (nonatomic, retain) IBOutlet UIPickerView* firstPicker;
#property (nonatomic, retain) IBOutlet FirstPickerViewDelegate* firstDelegate;
#end
Basically you need to drop an NSObject on your object list, and change it's class to FirstPickerViewDelegate, then make connections like this:
I feel I overelaborated this time, but I'm in a good mood today so whatever :P
About the main question: double check that listPicker is not nil at the time of pressing the button, if it is not, try to use
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
to track down the error.