我正在使用 cocos2d 开发 2D iPhone 游戏。我需要一个倒数计时器。如何在 cocos2d 中创建倒数计时器？
Nahid
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28456 次
6 回答
49
没有足够的代表来支持汤姆，但他是绝对正确的。在这个问题的背景下， NSTimer 是错误的解决方案。Cocos2d 框架提供了一个调度程序，它与其他游戏功能（如暂停/恢复）集成在一起（并且很可能在后台使用 NSTimer）。
来自上述链接的示例：
-(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
}
于 2009-03-03T08:54:17.793 回答
16
http://www.cocos2d-iphone.org/wiki/doku.php/prog_guide:best_practices
- 尽量不要使用 Cocoa 的 NSTimer。而是使用 cocos2d 自己的调度器。
- 如果你使用 cocos2d 调度器，你将拥有：
- 自动暂停/恢复。
- 当Layer（Scene、Sprite、CocosNode）进入舞台时，定时器会自动激活，离开舞台后会自动关闭。
- 您的目标/选择器将以增量时间调用...
于 2009-01-19T09:28:48.830 回答
4
在 cocos 2d 中，定时器有默认的更新部分。
试试这个：
[self schedule:@selector(update:)];
- (void)update:(ccTime)dt {
}
于 2010-11-26T13:18:29.467 回答
3
对于那些想要使用 NSTimer 而不是“schedule”方法的人，您可以创建一个如下所示的类：
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
于 2011-03-06T07:12:02.880 回答
-5
看看 NSTimer，它很可能提供任何需要的计时器功能。
于 2009-01-16T05:59:16.693 回答
-13
-(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
}
于 2009-01-19T08:58:36.537 回答