I have a method that chooses a random sprite node from an array to place on the screen. My app is crashing though. This is a snippet from the error message:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFConstantString decodeObjectForKey:]: unrecognized selector sent to instance 0x47b4'
This is the method I have written out.
-(SKSpriteNode *) gamePieces {
NSArray *things = [NSArray arrayWithObjects: #"piece1", #"piece2", #"piece3", nil];
int r = arc4random () % [things count];
SKSpriteNode *randomObject = [[SKSpriteNode alloc] initWithCoder:[things objectAtIndex:r]];
return randomObject;
}
Any ideas as to what the problem is?
As already mentioned by #HotLicks and #LearnCocos2d, -initWithCoder: is out of place here. Creating a new SKSpriteNode from scratch is typically done with one of the designated initializers (+spriteNodeWithColor:size:,+spriteNodeWithImageNamed: or spriteNodeWithTexture:). Assuming you just wish to create an SKSpriteNode with a random image, take a look at the following code.
- (SKSpriteNode *) randomGamePiece {
NSArray *filename = [NSArray arrayWithObjects: #"piece1", #"piece2", #"piece3", nil];
int r = arc4random () % [things count];
NSString * randomFilename = [things objectAtIndex:r];
SKSpriteNode *randomObject = [SKSpriteNode spriteWithImageNamed:randomFilename];
return randomObject;
}
I wholeheartedly recommend browsing through the Sprite Kit Programming Guide which contains many useful snippets and pointers for new and intermediate Sprite Kit programmers.
I've looked over the site for a while and I saw a few things but nothing worked for me. Extreme newbie here though.
I'm trying to make a 2 component picker, populated from arrays, populated from a dictionary, populated from a plist. The components populate, and I have a button that spins one component. The second button is meant to check answers (the first component has states which they try to match with capitals in the second component), but this is where it always crashes.
The error I get is as follows:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSPlaceholderString initWithFormat:locale:arguments:]: nil argument'
* First throw call stack:
(0x14b3022 0xeb3cd6 0x145ba48 0x145b9b9 0x916169 0x916ab4 0x3036 0x14b4e99 0x1914e 0x190e6 0xbfade 0xbffa7 0xbf266 0x3e3c0 0x3e5e6 0x24dc4 0x18634 0x139def5 0x1487195 0x13ebff2 0x13ea8da 0x13e9d84 0x13e9c9b 0x139c7d8 0x139c88a 0x16626 0x27ad 0x2715)
terminate called throwing an exception(lldb)
I'm not sure where I'm going wrong. I've done this with hard coded arrays, and it works fine. The code for the button is like so (please ignore the switch code, I haven't quite figured out how to make that work yet, I want the screen to turn green for correct answers and red for incorrect, but I'm more concerned with the app crashing!):
-(IBAction)checkAnswer;
{
NSInteger StateRow = [pickerCapital selectedRowInComponent:karrayStateComponent];
NSInteger CapitalRow =[pickerCapital selectedRowInComponent:karrayCapitalComponent];
NSString *state = [arrayState objectAtIndex:StateRow];
NSString *capital = [arrayCapital objectAtIndex:CapitalRow];
NSLog (#"%i",[pickerCapital selectedRowInComponent:karrayCapitalComponent]);
NSLog(#"%i", [pickerCapital selectedRowInComponent:karrayStateComponent]);
NSString *Title = [[NSString alloc]initWithFormat:#"You have selected %# as the capital of %#.", capital, state];
NSString *Message =[[NSString alloc]initWithFormat:lblMsg];
UIAlertView *alert =[[UIAlertView alloc]initWithTitle:Title message:Message delegate:#"" cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
if (StateRow == CapitalRow) {
lblMsg = #"You are correct!";
UIColor *myColor;
switch ([not sure what to use here]) {
case 0:
myColor = [UIColor greenColor];
break;
default:
break;
}
}
else {
lblMsg = #"Incorrect";
UIColor *myColor;
switch ([not sure what to use here]) {
case 0:
myColor = [UIColor redColor];
break;
default:
break;
}
}
}
If anyone can offer any sort of help on this, I would appreciate it greatly! Thank you!
Two things to check:
Where is lblMsg declared or assigned a value?
Are you sure capital and state are not nil from the calls to [arrayCapital objectAtIndex]?
Specifically: the NSString documentation states "Important: Raises an NSInvalidArgumentException if format is nil." for initWithFormat.
I have a class called KCBlackjack. The class contains this code:
playerHand = [[NSMutableArray alloc] init];
dealerHand = [[NSMutableArray alloc] init];
blackjack = [[KCBlackjack alloc] initWithNumberOfDecks:6];
[self deal];
[blackjack dealTo:playerHand dealer:dealerHand];
- (void)dealTo:(NSMutableArray *)player dealer:(NSMutableArray *)dealer {
// How many cards are left
NSLog(#"Cards in Deck: %d", [_decks count]);
// Deal to player then dealer
for (int i = 0; i <= 1; i++) {
[player addObject:[_decks lastObject]];
[_decks removeLastObject];
NSLog(#"%#", player);
if(_delegate && [_delegate respondsToSelector:#selector(didDistributeCard:withValue:)]) {
KCCard *aCard = (KCCard *)[player objectAtIndex:player.count-1];
[_delegate didDistributeCard:aCard to:player withValue:[aCard value]];
}
[dealer addObject:[_decks lastObject]];
[_decks removeLastObject];
NSLog(#"%#", dealer);
if(_delegate && [_delegate respondsToSelector:#selector(didDistributeCard:withValue:)]) {
KCCard *aCard = (KCCard *)[dealer objectAtIndex:dealer.count-1];
[_delegate didDistributeCard:aCard to:dealer withValue:[aCard value]];
}
}
NSLog(#"Done Dealing");
NSLog(#"Cards Remaining in Deck: %d", [_decks count]);
NSLog(#"Player: %#\n\n", player);
NSLog(#"Dealer: %#\n\n", dealer);
}
Inside of my game controller, I set player to my player array as well as the dealer his. When this is run however, it doesn't work. No objects are added to the player array that player or dealer is assigned.
When the code is in the game controller, it works, but not in this class. I figure something is not initializing, but in the game controller, the player and dealer are both initialized.
If you think of it from a OO perspective, dealer and player are really objects that should receive a message such as addCardToHand:(Card )aCard. The way you are doing it, Lucas has exactly right, you get a copy of his array which is not mutable. I'd much rather see some dot notation such as player.hand addCard:(Card)aCard if you don't want the player to handle the card himself (watch for card sharps! :-) ).
I think if you refactor with objects you can have clean code that works, and probably get rid of that delegation stuff (which is a bit confusing just reading).
Good luck - blackjack is fun!
Damien
I am creating a basic guessing game in iOS for my kids, and I think there are some fundamental gaps in my understanding of how I should be creating and releasing objects throughout the lifecycle of the app. I have been reading up on retain and release cycles but I think my issue is more to do with the fundamental architecture of the app and how I may be poorly trying to instantiate and then kill a few key objects of the app.
The problem centers around two specific classes.
I have a game class, which I have designed to hold all the information that the game requires to run. When it is init-ed, it holds all instance variables that point to arrays that hold strings such as the various clues, etc. It's basically a container for all the data that the game requires.
I have a game view controller, that creates and an instance of the game class and queries it so as to present on screen the various elements contained with the game object.
This works perfectly the fine. When the user starts a new game, a new instance of the game class is allocated and init-ed and away they go.
The issue comes in when I come to generate a new game. This happens a number of ways. Either The user finishes the game and starts another one or the user quits the current game and then starts a new one.
In my thinking, I would just release the game object and alloc and init a new one. However, I notice running on the device and looking through the profiler, that the game object isn't released at all.It's still, there and each instantiation of the game creates a new game object with the old one still sitting there with no pointers to it.
Fiddling around with the code, I noticed that I did not implement a dealloc method in the Game class...but when I try to do that, the app crashes, I suspect because I am trying to release a previously released object.
Ideally what I am trying to do is get rid of the old Game object, or replace the old one (overwrite) with a new one each time a new game is started.
However, is this approach wrong? Should I be doing it a completely different way? Such as only ever creating a single instance of the game class and rewriting a method inside that class so as to generate a new set of clues, etc everytime a new game starts and the GameViewController tells it to?
Is there a 'best practice' way to do this?
So you've got an idea of what I am doing, code is below for the GameViewController, where an instance of the Game class is created:
#import "GameViewController.h"
#implementation GameViewController
#synthesize game = _game;
-(void)startNewGameOfLevel:(NSInteger)level
{
if(!_game)
{
Game *g = [[Game alloc]initGamewithLevel:level];
[self setGame:g];
[g release]; g = nil;
}
[self set_currentlevel:[_game _currentLevel]];
// set up popover to show the rounds goal letter
[self setUpPopOver];
}
-(void)quitTheCurrentGameAndStartNewGame
{
[_game release]; _game = nil;
[self clearGamePlayingField];
animationStepIndex = 0;
[self startNewGameOfLevel: _currentlevel];
}
Game class (abridged) with the designated initializer of the Game class:
#import "Game.h"
#implementation Game
#synthesize arrayOfLowerCaseLetters = _arrayOfLowerCaseLetters;
#synthesize arrayOfPhrases= _arrayOfPhrases;
#synthesize goalLetter = _goalLetter;
#synthesize goalPhrase = _goalPhrase;
#synthesize gameLetterPool = _gameLetterPool;
#synthesize _indexForGoalLetter, _numberOfLevelsInGame, _currentLevel, _numberOfWhackHoles, _numberOfLettersInGameLetterPool;
-(id)initGamewithLevel:(NSInteger)level
{
[super init];
//create an array of lower case letters. These will
//contain the full alphabet of all possible letters
NSArray *arrayOfLCLetters = [[NSArray alloc] initWithObjects:#"a", #"b", #"c", #"d",#"e", #"f", #"g", #"h", #"i", #"j", #"k", #"l", #"m", #"n", #"o", #"p", #"qu", #"r", #"s", #"t", #"u", #"v", #"w", #"x",#"y", #"z",#"ch", #"sh", #"th", nil];
[self setArrayOfLowerCaseLetters: arrayOfLCLetters];
[arrayOfLCLetters release];arrayOfLCLetters = nil;
//create an array of phrases.
// These must correspond with each of the letters. e.g. a = apple.
NSArray *phrases= [[NSArray alloc ] initWithObjects:
#"apple",
#"butterfly",
#"cat",
#"dog",
#"egg",
#"frog",
#"ghost",
#"horse",
#"igloo",
#"jam",
#"kite",
#"leaf",
#"moon",
#"nut",
#"orange",
#"pig",
#"queen",
#"rabbit",
#"snake",
#"tree",
#"umbrella",
#"van",
#"water",
#"x-ray",
#"yak",
#"Zebra",
#"chair",
#"shoes",
#"thumb",
nil];
[self setArrayOfPhrases:phrases];
[phrases release]; phrases = nil;
//choose a random number to be the index reference for
// each goal letter and goal phrase.
[self set_indexForGoalLetter:(arc4random()%[_arrayOfLowerCaseLetters count])];
NSLog(#"index for goal letter is:, %i", _indexForGoalLetter);
//set Goal letter and goal phrase
[self setGoalLetter: [_arrayOfLowerCaseLetters objectAtIndex: _indexForGoalLetter]];
[self setGoalPhrase: [_arrayOfPhrases objectAtIndex:_indexForGoalLetter ]];
//set current level
[self set_currentLevel: level];
//[self set_currentLevel: 2];
//set number of whackholes by level
[self set_numberOfWhackHoles: [self numberOfWhackHolesByLevel:_currentLevel]];
//generate size of Letter pool by level
[self set_numberOfLettersInGameLetterPool:[self numberOfLettersInLetterPoolbyLevel:_currentLevel]];
////////////////////////////
/// Game letter pool
///////////////////////////
//set up array ton hold the pool of letters
NSMutableArray *gp = [[NSMutableArray alloc] initWithCapacity:_numberOfLettersInGameLetterPool];
[self setGameLetterPool: gp];
[gp release];gp = nil;
//add the goal letter to this pool
[_gameLetterPool addObject:_goalLetter];
int i = 1;
while (i < _numberOfLettersInGameLetterPool) {
NSString *letter = [_arrayOfLowerCaseLetters objectAtIndex:(arc4random()%[_arrayOfLowerCaseLetters count])];
if ([_gameLetterPool containsObject:letter] == false)
{
[_gameLetterPool addObject:letter];
i++;
}
}
NSLog(#"********** Game created ***************");
NSLog(#"pool of letters is: %#", [_gameLetterPool description]);
NSLog(#"****************************************");
NSLog(#"current goal letter is: %#", _goalLetter);
NSLog(#"****************************************");
NSLog(#"current goal phrase is: %#", _goalPhrase);
NSLog(#"****************************************");
return self;
}
-(void)dealloc
{
[super dealloc];
[_arrayOfLowerCaseLetters release]; _arrayOfLowerCaseLetters = nil;
[_arrayOfPhrases release]; _arrayOfPhrases = nil;
[_goalLetter release];_goalLetter = nil;
[_goalPhrase release]; _goalPhrase = nil;
[_gameLetterPool release];_gameLetterPool = nil;
}
The number one problem is that [super dealloc] must be the absolute last thing you do in -dealloc. This is because it is the dealloc method in NSObject that actually frees the memory, so by the time you get back to it, your instance variable pointers may already be garbage.
Other issues:
In init, do self = [super init]; The super object is allowed to return a different self pointer on init.
startNewGameOfLevel: and quitTheCurrentGameAndStartNewGame should use the property, not the bare instance variable.
-(void)startNewGameOfLevel:(NSInteger)level
{
if(![self game])
{
Game *g = [[Game alloc]initGamewithLevel:level];
[self setGame:g];
[g release]; g = nil;// g = nil, not necessary when it's about to go out of scope
}
[self set_currentlevel:[[self game] _currentLevel]]; // don't use _ to start methods - Apple reserves this convention
// set up popover to show the rounds goal letter
[self setUpPopOver];
}
-(void)quitTheCurrentGameAndStartNewGame
{
[self setGame: nil];
[self clearGamePlayingField];
animationStepIndex = 0;
[self startNewGameOfLevel: _currentlevel];
}
There are probably other issues in the body of your code - make sure you build with static analysis enables - it will catch many of them.
I am running into some serious memory leaks in one of my applications I am building. I have a UINavigatonController that is inside a UITabBarview. Inside the NavView is a MKMap view. When you click an accessory button on a callout a detail view is loaded. In that detail view I am trying to populate a table from a plist using a for(object in array) loop. The plist is an array of dictionaries. I am running though the dictionaries to find one with a key that is the title of the callout and then get an array from inside that dictionary. It all works fine in the simulaor but I am getting massive memory leaks doing it the way I am. Any Idea whats going on?
- (void)viewDidLoad {
self.title = #"Route Details";
NSString *path = [[NSBundle mainBundle] pathForResource:#"stopLocation" ofType:#"plist"];
holderArray = [[NSMutableArray alloc] initWithContentsOfFile:path];
[self getRouteArray];
routeDetails.delegate = self;
routeDetails.dataSource = self;
}
-(void)getRouteArray{
for (NSMutableDictionary *dictionary in holderArray) {
//NSString *stopName = [dictionary objectForKey:#"StopName"];
//NSString *stopName = [[NSString alloc] initWithString:[dictionary objectForKey:#"StopName"]];
BOOL testString = [currentRoute isEqualToString:[dictionary objectForKey:#"StopName"]];
if (testString) {
routeArray = [[NSMutableArray alloc] initWithArray:[dictionary objectForKey:#"RouteService"]];
}
}
}
- (void)dealloc {
[routeArray release];
[routeDetails release];
[super dealloc];
}
holderArray is an ivar and so is route array. As you can see I have tried a few ways of allocating the nstrings and arrays but all seem to yield the same leaks. According to the performance tool I am leaking from NSCFString, NSCFDictionary, and the NSCFArry. I released the routeArray in the dealloc and it works fine, but if I release holderArray it crashes whenever I go back to my map from the detail view. I guess I am just really unsure as to how to deal with the strings and dictionary used in the for loop.
Just to add the detail view is being created like so:
- (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control{
NSString *selectedRouteName = [NSString stringWithFormat:#"%#",view.annotation.title];
RouteDetailView *rdc = [[RouteDetailView alloc] initWithNibName:#"RouteDetailView" bundle:nil];
[rdc setCurrentRoute:selectedRouteName];
[self.navigationController pushViewController:rdc animated:YES];
[rdc release];
}
Sorry if any of the above is unclear. Let me know and I can try to rephrase it.
Will testString be true for at most one key in holderArray? If so, you should probably break out of the loop after setting routeArray. If not, then you may be setting routeArray multiple times, and all but the last array you assigned to it would be leaked.
Also, I don't see you releasing holderArray.