Como posso criar uma contagem regressiva para cocos2d?

Question

Estou desenvolvendo um iPhone jogo 2D usando cocos2d. Eu preciso de um temporizador de contagem regressiva. Como posso criar uma contagem regressiva em cocos2d?

Answer 1

Não rep suficiente para upvote Tom, mas ele está absolutamente certo. No contexto desta questão, NSTimer é a solução errada. O quadro Cocos2d fornece um programador que se integra com outros jogo apresenta como Pause / Resume (e provavelmente usa NSTimer sob o capô).

Exemplo da ligação acima:

-(id) init
{
    if( ! [super init] )
        return nil;

    // schedule timer
    [self schedule: @selector(tick:)];
    [self schedule: @selector(tick2:) interval:0.5];

    return self;
}

-(void) tick: (CCTime) dt
{
    // bla bla bla
}

-(void) tick2: (CCTime) dt
{
    // bla bla bla
}

Answer 2

http://www.cocos2d-iphone.org/wiki /doku.php/prog_guide:best_practices

• Tente não para usar NSTimer do Cacau. Em vez disso próprio agendador uso de cocos2d.
• Se você usar o programador cocos2d, você terá:
  • pausa automática / currículo.
  • quando o Layer (Cena, Sprite, CocosNode) entra no palco o temporizador será ativado automaticamente, e quando ele deixa o palco será desactivado automaticamente.
  • Seu alvo / seletor será chamado com um tempo delta ...

Answer 3

Em cocos 2d há seção de atualização padrão para timer.

Tente isto:

[self schedule:@selector(update:)];
- (void)update:(ccTime)dt {
}

Answer 4

Para aqueles que querem usar NSTimer em vez do método "schedule", você pode criar uma classe, como a seguir:

ZIMCountdownTicker.h

#import <Foundation/Foundation.h>

extern NSString * const ZIMCountdownTickerTickAction;
extern NSString * const ZIMCountdownTickerResetAction;

@protocol ZIMCountdownTickerProtocol;

/*!
 @class             ZIMCountdownTicker
 @discussion        This class creates a countdown ticker.
 @updated           2011-03-05
 */
@interface ZIMCountdownTicker : NSObject {

    @private
        NSTimer *_timer;
        id<ZIMCountdownTickerProtocol> _delegate;
        NSTimeInterval _interval;
        double _period;
        double _value;

}

/*!
 @method                initWithDelegate:withTimeInterval:forTimePeriod:
 @discussion            This method instantiate an instance of this class with the specified parameters.
 @param delegate        A reference to a class that has implemented ZIMCountdownTickerProtocol.
 @param interval        The time interval in seconds to be used when running the countdown ticker.
 @param period          The time period in seconds for which countdown ticker will run.
 @updated               2011-03-05
 */
- (id) initWithDelegate: (id<ZIMCountdownTickerProtocol>)delegate withTimeInterval: (NSTimeInterval)interval forTimePeriod: (double)period;
/*!
 @method                start
 @discussion            This method will start the countdown ticker.
 @updated               2011-03-05
 */
- (void) start;
/*!
 @method                stop
 @discussion            This method will stop the countdown ticker.
 @updated               2011-03-05
 */
- (void) stop;
/*!
 @method                reset
 @discussion            This method will reset the countdown ticker.
 @updated               2011-03-06
 */
- (void) reset;
/*!
 @method                value
 @discussion            This method will return the countdown ticker's current value; however, using this method will cause
                    the ticker to stop.
 @return                The countdown ticker's current value.
 @updated               2011-03-05
 */
- (double) value;

@end

@protocol ZIMCountdownTickerProtocol <NSObject>

@optional
/*!
 @method                countdownTicker:didUpdateValue:withAction:
 @discussion            This method will notify the delegate with the current value.
 @param ticker          A reference to tiggering ticker.
 @param value           The current value.
 @param action          The action that tiggered this method.
 @updated               2011-03-05
 */
- (void) countdownTicker: (ZIMCountdownTicker *)ticker didUpdateValue: (double)value withAction: (NSString *)action;
/*!
 @method                countdownTickerDidFinish:
 @discussion            This method will notify the delegate that the countdown ticker finished.
 @param ticker          A reference to tiggering ticker.
 @updated               2011-03-05
 */
- (void) countdownTickerDidFinish: (ZIMCountdownTicker *)ticker;

@end

ZIMCountdownTicker.m

// Ziminji Classes
#import "ZIMCountdownTicker.h"

NSString * const ZIMCountdownTickerTickAction = @"ticker.tick";
NSString * const ZIMCountdownTickerResetAction = @"ticker.reset";

/*!
 @category          ZIMCountdownTicker (Private)
 @discussion        This category defines the prototypes for this class's private methods.
 @updated           2011-03-05
 */
@interface ZIMCountdownTicker (Private)
    /*!
     @method            countdown:
     @discussion        This method is called by the timer to decrement the counter's value and will send
                    the delegate the updated value.
     @param timer       The timer currently in use.
 @updated           2011-03-06
    */
    - (void) countdown: (NSTimer *)timer;
@end

@implementation ZIMCountdownTicker

- (id) initWithDelegate: (id<ZIMCountdownTickerProtocol>)delegate withTimeInterval (NSTimeInterval)interval forTimePeriod: (double)period {
    if (self = [super init]) {
        _delegate = delegate;
        _interval = interval;
        _period = period;
        _value = period;
        _timer = nil;
    }
    return self;
}

- (void) start {
    if (_timer == nil) {
        _timer = [NSTimer scheduledTimerWithTimeInterval: _interval target: self selector: @selector(countdown:) userInfo: nil repeats: YES];
    }
}

- (void) stop {
    if (_timer != nil) {
        [_timer invalidate];
        _timer = nil;
    }
}

- (void) reset {
    [self stop];
    _value = _period;
    if ((_delegate != nil) && [_delegate respondsToSelector: @selector(countdownTicker:didUpdateValue:withAction:)]) {
        [_delegate countdownTicker: self didUpdateValue: _value withAction: ZIMCountdownTickerResetAction];
    }
}

- (double) value {
    [self stop];
    return _value;
}

- (void) countdown: (NSTimer *)timer {
    _value -= 1;
    if ((_delegate != nil) && [_delegate respondsToSelector: @selector(countdownTicker:didUpdateValue:withAction:)]) {
        [_delegate countdownTicker: self didUpdateValue: _value withAction: ZIMCountdownTickerTickAction];
    }
    if (_value <= 0) {
        [self stop];
        if ((_delegate != nil) && [_delegate respondsToSelector: @selector(countdownTickerDidFinish:)]) {
            [_delegate countdownTickerDidFinish: self];
        }
    }
}

- (void) dealloc {
    if (_delegate != nil) {
        [_delegate release];
    }
    if (_timer != nil) {
        [_timer invalidate];
    }
    [super dealloc];
}

@end

Answer 5

Olhe para NSTimer, pode provavelmente fornecer qualquer funcionalidade temporizador necessária.

NSTimer referência de classe

Answer 6

-(id) init
{
    if( ! [super init] )
        return nil;

    // schedule timer
    [self schedule: @selector(tick:)];
    [self schedule: @selector(tick2:) interval:0.5];

    return self;
}

-(void) tick: (ccTime) dt
{
    //some function here
}

-(void) tick2: (ccTime) dt
{
    //some function here
}