- (IBAction)onTest:(id)sender { BlockDemo *demo = [[BlockDemo alloc]init];  __weak typeof(BlockDemo) *weakDemo = demo;  [demo setExecuteFinished:^{ if (weakDemo.resultCode == 200) { NSLog(@"call back ok."); } }]; [demo executeTest]; }…

一个用Block实例变量语法,当有一个参考的实例变量,常引起retain cycle. capturing self strongly in this block is likely to lead to a retain cycle _items = [[NSMutableArray alloc] init]; _block = ^{ [_items addObject:@"Hello!"]; //_block引用了_items,导致retain cycle. }; 写成以下格式 _…

以形如 _fontValueChangedBlock = ^(){ [self.fontSmallButton addTarget:self action:@selector(btnFontSmallClicked) forControlEvents:UIControlEventTouchUpInside]; }; 的代码为例,这个代码运行会报警告."capturing self strongly in this block is likely to lead to a retain cycle…

警告:ARC Retain Cycle Capturing 'self' strongly in this block is likely to lead to a retain cycle 代码: self.refreshHeader.beginRefreshingBlock=^(){ // 后台执行: dispatch_async(dispatch_get_global_queue(0, 0), ^{ sleep(2); dispatch_async(dispatch_get_main_qu…

xcode arc 下使用 block警告 Capturing [an object] strongly in this block is likely to lead to a retain cycle” in ARC-enabled code 解决方法: 方法一: ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:[NSURL URLWithString:Api]]; __block ASIHTTPRequest *brRequ…

<span style="background-color: rgb(248, 248, 248); font-family: 'PT Sans', Geogia, Baskerville, 'Hiragino Sans GB', serif; ">警告:Captureing ‘self’ strongly in this block is likely to lead to a retain cycle</span> 一个使用Block语法的实例变量,在引用另…

一个使用Block语法的实例变量,在引用另一个实例变量的时候,经常会引起retain cycle.这个问题在使ASIHTTPRequest的block语法的时候会时不时的碰到.这个问题困扰了我这个小白很久.终于有一天,在Advanced Mac OS X Programming上,看到了这个问题的解决方案. 先用代码描述一下症状: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 /* Vi…

让我们长话短说.请参阅如下代码: - (IBAction)didTapUploadButton:(id)sender { NSString *clientID = @"YOUR_CLIENT_ID_HERE"; NSString *title = [[self titleTextField] text]; NSString *description = [[self descriptionTextField] text]; [[UIApplication sharedApplicati…

作者:fengsh998原文地址:http://blog.csdn.net/fengsh998/article/details/38090205转载请注明出处如果觉得文章对你有所帮助,请通过留言或关注微信公众帐号fengsh998来支持我,谢谢! http://blog.csdn.net/fengsh998/article/details/38090205 本文不讲block如何声明及使用,只讲block在使用过程中暂时遇到及带来的隐性危险. 主要基于两点进行演示: 1.block 的循环引用(…

本系列博文总结自<Pro Multithreading and Memory Management for iOS and OS X with ARC> 在上一篇文章中,我们讲了很多关于 block 和基础变量的内存管理,接着我们聊聊 block 和对象的内存管理,如 block 经常会碰到的循环引用问题等等. 获取对象 照例先来段代码轻松下,瞧瞧 block 是怎么获取外部对象的 /********************** capturing objects **************…