- 浏览: 568909 次
- 性别:
- 来自: 广州
文章分类
最新评论
-
JYY282:
[i][/i]
Ecshop与Shopex的比较 -
qq247890212:
我也遇见这问题了,真诡异。重新下载个猫换了就好了。 太浪费时间 ...
诡异:ClassNotFoundException: org.springframework.web.filter.CharacterEncoding
From : http://o0o0o0o.iteye.com/blog/1326772
一:operations(任务)
cocoa提供了三种不同的operations
1:Block operations(NSBlockOperation
)
These f
acilitate the execution of
one or more block objects.
- #import <UIKit/UIKit.h>
- @inter<span>f</span>ace OperationsAppDelegate : NSObject <UIApplicationDelegate> {
- UIWindow *window;
- NSBlockOperation *simpleOperation;
- }
- @property (nonatomic, retain) IBOutlet UIWindow *window;
- @property (nonatomic, retain) NSBlockOperation *simpleOperation;
- @end
- #import "OperationsAppDelegate.h"
- @implementation OperationsAppDelegate
- @synthesize window;
- @synthesize simpleOperation;
- - (BOOL ) application:(UIApplication *)application did<span>F</span>inishLaunchingWithOptions:(NSDictionary *)launchOptions {
- /* Here is our block */
- NSBlockOperation *newBlockOperation = [NSBlockOperation blockOperationWithBlock:^{
- NSLog(@"Main Thread = %@" , [NSThread mainThread]);
- NSLog(@"Current Thread = %@" , [NSThread currentThread]);
- NSUInteger counter = 0;
- for (counter = 0;counter < 1000;counter++){
- NSLog(@"Count = %lu" , (unsigned long )counter);
- }
- }];
- /* Make sure we keep the reference somewhere */
- self.simpleOperation = newBlockOperation;
- /* Start the operation */
- [self.simpleOperation start];
- /* Print something out just to test i<span>f</span> we have to wait
- <span>f</span>or the block to execute its code or not */
- NSLog(@"Main thread is here" );
- [window makeKeyAndVisible];
- return YES;
- }
- - (void )dealloc {
- [simpleOperation release];
- [window release];
- [super dealloc];
- }
- @end
2:Invocation operations(NSInvocationOperation
)
These allow you to invoke a method in another, currently existing object.
NSNumber *simpleObject = [NSNumber numberWithInteger:123];
NSInvocationOperation *newOperation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(simpleOperationEntry:) object:simpleObject];
[newOperation start];
调用start方法执行改任务
- #import <UIKit/UIKit.h>
- @interface OperationsAppDelegate : NSObject <UIApplicationDelegate> {
- UIWindow *window;
- NSInvocationOperation *simpleOperation;
- }
- @property (nonatomic, retain) IBOutlet UIWindow *window;
- @property (nonatomic, retain) NSInvocationOperation *simpleOperation;
- @end
- - ( void ) simpleOperationEntry:(id)paramObject{
- NSLog(@"Parameter Object = %@" , paramObject);
- NSLog(@"Main Thread = %@" , [NSThread mainThread]);
- NSLog(@"Current Thread = %@" , [NSThread currentThread]);
- }
- - (BOOL ) application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
- NSNumber *simpleObject = [NSNumber numberWithInteger:123];
- NSInvocationOperation *newOperation =[[NSInvocationOperation alloc] initWithTarget:self selector:@selector(simpleOperationEntry:) object:simpleObject];
- self.simpleOperation = newOperation;
- [newOperation release];
- [self.simpleOperation start];
- [window makeKeyAndVisible];
- return YES;
- }
- - (void )dealloc {
- [simpleOperation release];
- [window release];
- [super dealloc];
- }
3:Plain operations(简单的任务)NSOperation的子类
These are plain operation classes that need to be subclassed. The code to be executed
will be written inside the main method
of
the operation object.
这里的operationId属性不是必须的
- @implementation MyTask
- @synthesize operationId;
- - (void )main{
- NSLog(@"task %i run … " ,operationId);
- [NSThread sleep<span>F</span>orTimeInterval:10];
- NSLog(@"task %i is <span>f</span>inished. " ,operationId);
- }
- @end
必须
- (void)main;方法,[MyTask start]是执行main方法
二:任务队列(NSOperationQueue)
NSOperationQueue *newOperationQueue = [[NSOperationQueue alloc] init];
[ newOperationQueue addOperation:Operation];
以上三种Operation都可以添加到NSOperationQueue中,添加后立即被执行。
NSOperationQueue 可以设置最大并行执行任务数。默认值为-1无限制。
三:多个任务之间存在依赖关系
设置方式:
[self.firstOperation addDependency :self.secondOperation];
dependency:附属的意思
把secondOperation做为firstOperation的附属。因此先执行secondOperation,再执行firstOperation 。
四:延时执行某个方法
1: performSelector:withObject:afterDelay:
- - ( void ) connectionHasFailedWithError:(NSError *)paramError onRemoteURL:(NSURL *)paramRemoteURL{
- /* We failed to download the file. Attempt to download it again after 3 seconds */
- [self performSelector:@selector(attemptToDownloadRemoteURL:) withObject:paramRemoteURL afterDelay:3.0f];
- }
- - (void ) attemptToDownloadRemoteURL:(NSURL *)paramRemoteURL{
- /* Attempt to download the remote file again here by initializing
- a new connection ... */
- }
该方法只能接受一个参数。如果需要传递多个参数怎么办呢???
让selector调用的方法接受的参数类型修改为Dictionary类型。
(1)如果调用的selector不接受参数则,withObject:nil
(2) 通过performSelector:withObjcet:afterDelay调用的方法不能有返回值
2:取消延时执行的方法
(1)cancelPreviousPerformRequestsWithTarget:
(2) cancelPreviousPerformRequestsWithTarget:selector:object:
五:NSTimer
1:scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:
2:invalidate
调用invalidate方法,不仅是释放NSTimer,还释放userinfo对象。
如果repeats设置为NO,NSTimer在调用完成之后就知道失效,随即释放userinfo对象
3:scheduledTimerWithTimeInterval:invocation:repeats:
- - ( void ) startPainting{
- SEL selectorToCall = @selector(paint:);
- NSMethodSignature *methodSignature = [[self class ] instanceMethodSignatureForSelector:selectorToCall];
- NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:methodSignature];
- [invocation setTarget:self];
- [invocation setSelector:selectorToCall];
- /* Start a scheduled timer now */
- NSTimer *newTimer =[NSTimer scheduledTimerWithTimeInterval:1.0
- invocation:invocation
- repeats:YES];
- self.paintingTimer = newTimer;
- }
4:timerWithTimeInterval:target:selector:userInfo:repeats:
(用该方式,需要把timer添加到runloop中)
- - ( void ) startPainting{
- NSTimer *newTimer = [NSTimer timerWithTimeInterval:1.0
- target:self
- selector:@selector(paint:)
- userInfo:nil
- repeats:YES];
- self.paintingTimer = newTimer;
- [[NSRunLoop currentRunLoop] addTimer:self.paintingTimer forMode:NSDefaultRunLoopMode];
- }
5:timerWithTimeInterval:invocation:repeats:
(用该方式,需要把timer添加到runloop中)
- - ( void ) startPainting{
- SEL selectorToCall = @selector(paint:);
- NSMethodSignature *methodSignature =[[self class ] instanceMethodSignatureForSelector:selectorToCall];
- NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:methodSignature];
- [invocation setTarget:self];
- [invocation setSelector:selectorToCall];
- NSTimer *newTimer = [NSTimer timerWithTimeInterval:1.0
- invocation:invocation
- repeats:YES];
- self.paintingTimer = newTimer;
- [[NSRunLoop currentRunLoop] addTimer:self.paintingTimer
- forMode:NSDefaultRunLoopMode];
- }
6:NSTimer 响应函数定义格式
并需有一个NSTimer *类型的参数
六:NSThread
1:initWithTarget:selector:object:
2:detachNewThreadSelector:toTarget: withObject:
以上两种方式,selector调用的函数,必须声明自己的NSAutoreleasePool
3:performSelectorInBackground: withObject:
一个简单的方法来创建线程,而无需直接处理线程。
4:start
调用start方法启动线程
5:cancel
调用cancel方法,并把变量赋值为nil
6:cancel vs exit
对于线程调用cancel方法停止,不要调用exit,因为exit方法没有给线程清理自己并释放资源的时间
7:线程的内存泄露
- - ( void ) newThreadEntryPoint{
- /* A thread without an autorelease pool to test the following code */
- //NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
- /* This WILL cause a memory leak */
- [self performSelector:@selector(allocateSomething)];
- /* This will NOT cause a memory leak */
- [self performSelectorOnMainThread:@selector(allocateSomething)
- withObject:nil
- waitUntilDone:YES];
- //[pool release];
- }
- - (void ) allocateSomething{
- NSBundle *mainBundle = [NSBundle mainBundle];
- NSString *imagePath = [mainBundle pathForResource:@"MyImage" ofType:@ "png" ];
- NSData *imageData = [NSData dataWithContentsOfFile:imagePath];
- UIImage *myImage = [[[UIImage alloc] initWithData:imageData] autorelease];
- /* Do something with the image here */
- }
- - (void )viewDidLoad {
- [NSThread detachNewThreadSelector:@selector(newThreadEntryPoint)
- toTarget:self
- withObject:nil];
- }
UIImage *myImage = [[[UIImage alloc] initWithData:imageData] autorelease];-------------自动释放池的范围
/* This WILL cause a memory leak */
[self performSelector:@selector(allocateSomething)];
调用改方法myImage 对象被添加进该新建线程的自动释放池,但因为在这里没有声明NSAutoreleasePool 造成内存泄露
/* This will NOT cause a memory leak */
[self performSelectorOnMainThread:@selector(allocateSomething)
withObject:nil
waitUntilDone:YES];
调用改方法myImage 对象被放进主线程的自动释放池,在主线程销毁是被自动释放
发表评论
-
Objective-C 与 C++ 的异同
2013-04-02 12:03 1352http://www.cnblogs.com/y041039 ... -
Cocos2D-X是全球知名的开源跨平台手机游戏引擎
2013-01-22 10:05 2704http://www.oschina.net/p/cocos ... -
iOS Keyboard 键盘高度变化 自适应
2013-01-15 15:43 3214[[NSNotificationCenter default ... -
iOS使用自定义字体
2012-11-27 12:11 12070From: http://blog.csdn.net/csy1 ... -
4 款类似 Facebook/Path 切换效果的 iOS 组件
2012-11-27 12:03 2079From: http://blog.csdn.net/lia ... -
Path 2.0的UI界面设计详细介绍
2012-11-27 11:56 1422如Path的创始人Dave Morin ... -
史上最全的App Store邮箱列表
2012-11-27 11:51 1212From: http://roybaby.blog.51cto ... -
iOS从info.plist 获取项目的名称及版本号
2012-11-16 10:54 1564From: http://blog.sina.com.cn/s ... -
MapKit annotation drag and drop with callout info update
2012-10-13 10:38 2359http://hollowout.blogspot ... -
NSArray 或NSDictionary 调用writeToFile方法失败原因
2012-08-31 10:03 4418NSArray 或NSDictionary 调用writeTo ... -
如何让IOS应用从容地崩溃
2012-08-30 15:25 1568From: http://www.cocoachina.com ... -
iOS中判断设备系统版本
2012-08-29 17:17 31665在iOS开发中,经常要考虑系统的向下兼容,如果使用 ... -
iOS 汉字转拼音
2012-08-21 16:42 1418From: http://www.cnblogs.com/v2 ... -
iOS模拟器截图工具
2012-08-17 16:35 1577From: http://magicalboy.com/ios ... -
XCode下的iOS单元测试
2012-08-10 17:47 1116From: http://mobile.51cto.com/ ... -
AFNetworking
2012-08-08 10:54 4615AFNetworking on github: https:/ ... -
Wrapping Conventions
2012-08-01 15:54 775Wrapping Conventions ... -
Core Animation如何使显式动画结束时的值直接作用Layer
2012-08-01 14:51 3744(1)使用隐式动画会直接改变layer的属性值,如: ima ... -
How To Debug Memory Leaks with XCode and Instruments Tutoria
2012-07-31 16:30 1015From: http://www.raywenderlich. ... -
Using Properties in Objective-C Tutorial
2012-07-31 16:27 877From: http://www.raywenderlich. ...
相关推荐
在主线程上面创建定准定时器,一个简单的demo
多种方法实现计时器,包括通信获取服务器端系统时间,多线程实现,NSTimer实现等等 http://blog.csdn.net/dingxiaowei2013/article/details/9864279
最近在调研 iOS app 中存在的各种卡顿现象以及解决方法。 iOS App 出现卡顿(stall)的概率可能超出大部分人的想象,尤其是对于大公司旗舰型 App。一方面是由于业务功能不停累积,各个产品团队之间缺乏协调,大家都...
ios 完美使用gcd 哪怕菜鸟都会使用的线程操作,队列,定时器,等待等
单任务进度的监听是NSProgress最简单的一种运用场景,我们来用定时器模拟一个耗时任务,示例代码如下: @interface ViewController () { NSProgress * progress; } @end @implementation ViewController - (void)...
使用CADisplayLink创建一个刷新定时器,设置帧刷新调用方法时间,然后加入mainRunLoop里面执行。具体加在主线程的RunLoop还是子线程的RunLoop可根据自己项目进行修改。
//判断定时器的指针是否存在(定时器的对象是否存在) if(_tim){ //必须在定时器失效以后将定时器的指针至为空 [_tim invalidate]; invalidate使…无效 _tim=nil; }else{ _tim=[NSTimer ...
6.NSTimer定时器 准备资料: 《iOS与OS X多线程和内存管理》《52个有效方法》 实践: Swift 《objccn-swifter-tips》《objccn-advanced-swift》 UIKit UIView、UIViewController生命周期 事件响应链 UItableView优化 ...
使用线程实现的简单易用的定时器。 信号量。 线程组。 简单易用的线程池,可以异步或同步执行任务,支持functional 和 lambad表达式。 工具库 文件操作。 std::cout风格的日志库,支持颜色高亮、代码定位、异步打印...
鹏哥哥放大镜 封装好 线程安全 无泄漏 简单易用 移植性好 使用中有问题 请前去GitHub与我联系 感谢您的使用 对您有帮助的话 送我一颗星星可好 使用简介: 1.PGGMagnigierView导入放大镜类 也可以在这里面进行镜框...
● 构建使用了日期、定时器与内存管理的应用 ● 如何在其他平台上使用Objective-C 凭借深入的代码示例与清晰的解释说明,本书将帮助你轻松解决iOS开发人员每天都 会面临的挑战。通过使用书中介绍的知识与技能,...
Unity3D音乐开关与音量条 Unity3D教程:GUILayout.Window和GUI.Window的区别 在游戏中改变地形高度 教你如何创建unity3d多个定时器,以及定时器的其他操作 Unity3D使用LitJson解析服务器上的JSON IOS下文件保存和...
一个基于C++11简单易用的轻量级网络编程框架项目特点基于...线程库使用线程实现的简单易用的定时器。信号量。线程组。简单易用的线程池,可以异步或同步执行任务,支持functional 和 lambad表达式。工具库文件操作。std
今天博客中所涉及的内容并不复杂,都是一些平时常见的一些问题,通过这篇博客算是对UITableView中使用定时器的几种方式进行总结。本篇博客会给出在TableView中使用NSTimer或者DispatchSourcer中常见的五种方式。当然...
源码CorePPTVC,幻灯终结者:超简单、酷且炫、多样式、...支持定时器自动切换且界面push定时器停止. .8.支持幻灯点击事件回调. .9.幻灯框架可任意扩展与自定义. .9.内部很多控件均可高度自定义样式,灵活性非常大.
支持定时器自动切换且界面push定时器停止..8.支持幻灯点击事件回调..9.幻灯框架可任意扩展与自定义..9.内部很多控件均可高度自定义样式,灵活性非常大.使用示例 //定义数据模型。如果数据来自远程服务器,可一键转...