NSTimer保留目标对象引起循环引用的解决办法

直接上代码：
扩充NSTimer功能，用block打破循环引用，创建类别实现。代码如下：

NSTimer+BlockSupport.h

//  
//  NSTimer+BlockSupport.h  
//  NewDemo  
//  
//  Created by sj_w on 16/3/24.  
//  Copyright © 2016年 sj_w. All rights reserved.  
//  
  
#import <Foundation/Foundation.h>  
  
@interface NSTimer (BlockSupport)  
  
+ (NSTimer *)yy_scheduledTimerWithTimeInterval:(NSTimeInterval)interval  
                                          block:(void(^)())block  
                                        repeats:(BOOL)repeats;  
  
@end  

NSTimer+BlockSupport.m

//  
//  NSTimer+BlockSupport.m  
//  NewDemo  
//  
//  Created by sj_w on 16/3/24.  
//  Copyright © 2016年 sj_w. All rights reserved.  
//  
  
#import "NSTimer+BlockSupport.h"  
  
@implementation NSTimer (BlockSupport)  
  
+ (NSTimer *)yy_scheduledTimerWithTimeInterval:(NSTimeInterval)interval  
                                          block:(void(^)())block  
                                        repeats:(BOOL)repeats  
{  
    return [self scheduledTimerWithTimeInterval:interval  
                                         target:self  
                                       selector:@selector(yzt_blockInvoke:)  
                                       userInfo:[block copy]  
                                        repeats:repeats];  
}  
  
+ (void)yzt_blockInvoke:(NSTimer *)timer {  
    void (^block) () = timer.userInfo;  
    if (block) {  
        block();  
    }  
}  
  
@end  

打完收功。。。