NSTimer解除循环引用

NSTimer作为一个经常使用的类，却有一个最大的弊病，就是会强引用target。造成调用timer很麻烦。稍有不慎就造成内存泄漏。

下面就是为解决问题做的封装。

直接上代码：

#import <Foundation/Foundation.h>

@interface LZLTimer :
NSObject

-(void)startTimerInterval:(NSTimeInterval)ti target:aTarget selector:(SEL)selector
userInfo:(id)userInfo repeats:(BOOL)yesOrNo;

@end

#import "LZLTimer.h"

@interface LZLWeakTimerTarget :
NSObject

@property (nonatomic,weak)
id target;

@property (nonatomic,assign)
SEL selector;

- (void)timerDidFire:(NSTimer *)timer;

@end

@implementation LZLWeakTimerTarget

- (void)timerDidFire:(NSTimer *)timer {

if(_target) {

//消除arc警告

IMP imp = [_target
methodForSelector:_selector];

if ([NSStringFromSelector(_selector)
hasSuffix:@":"]) {

void (*func)(id,
SEL, id) = (void *)imp;

func(_target,
_selector, timer);

}else {

void (*func)(id,
SEL) = (void *)imp;

func(_target,
_selector);

}

} else {

[timer invalidate];

}

}

@end

@interface LZLTimer () {

NSTimer *_timer;

}

@end

@implementation LZLTimer

-(void)dealloc {

if (_timer!=nil) {

[_timer
invalidate];

_timer =
nil;

}

}

-(void)startTimerInterval:(NSTimeInterval)ti target:aTarget selector:(SEL)selector
userInfo:(id)userInfo repeats:(BOOL)yesOrNo {

if (nil ==
_timer) {

WMWeakTimerTarget *weakTarget = [[WMWeakTimerTarget
alloc] init];

weakTarget.target = aTarget;

weakTarget.selector = selector;

_timer = [NSTimer
scheduledTimerWithTimeInterval:ti
target:weakTarget selector:@selector(timerDidFire:)
userInfo:userInfo repeats:yesOrNo];

}

}

@end