标签:url ace 问题 oci 处理 htm 初始化 ref upload
NSThread
哎呀,它面向对象,再去看看苹果提供的API,对比一下Pthreads,简单明了,人生仿佛又充满了阳光和希望,我们先来一看一下系统提供给我们的API自然就知道怎么用了,来来来,我给你注释一下啊:
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@interface NSThread : NSObject //当前线程 @property (class, readonly, strong) NSThread *currentThread; //使用类方法创建线程执行任务 + (void)detachNewThreadWithBlock:(void (^)(void))block API_AVAILABLE(macosx(10.12), ios(10.0), watchos(3.0), tvos(10.0)); + (void)detachNewThreadSelector:(SEL)selector toTarget:(id)target withObject:(nullable id)argument; //判断当前是否为多线程 + (BOOL)isMultiThreaded; //指定线程的线程参数,例如设置当前线程的断言处理器。 @property (readonly, retain) NSMutableDictionary *threadDictionary; //当前线程暂停到某个时间 + (void)sleepUntilDate:(NSDate *)date; //当前线程暂停一段时间 + (void)sleepForTimeInterval:(NSTimeInterval)ti; //退出当前线程 + (void)exit; //当前线程优先级 + (double)threadPriority; //设置当前线程优先级 + (BOOL)setThreadPriority:(double)p; //指定线程对象优先级 0.0~1.0,默认值为0.5 @property double threadPriority NS_AVAILABLE(10_6, 4_0); //服务质量 @property NSQualityOfService qualityOfService NS_AVAILABLE(10_10, 8_0); //线程名称 @property (nullable, copy) NSString *name NS_AVAILABLE(10_5, 2_0); //栈区大小 @property NSUInteger stackSize NS_AVAILABLE(10_5, 2_0); //是否为主线程 @property (class, readonly) BOOL isMainThread NS_AVAILABLE(10_5, 2_0); //获取主线程 @property (class, readonly, strong) NSThread *mainThread NS_AVAILABLE(10_5, 2_0); //初始化 - (instancetype)init NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER; //实例方法初始化,需要再调用start方法 - (instancetype)initWithTarget:(id)target selector:(SEL)selector object:(nullable id)argument NS_AVAILABLE(10_5, 2_0); - (instancetype)initWithBlock:(void (^)(void))block API_AVAILABLE(macosx(10.12), ios(10.0), watchos(3.0), tvos(10.0)); //线程状态,正在执行 @property (readonly, getter=isExecuting) BOOL executing NS_AVAILABLE(10_5, 2_0); //线程状态,正在完成 @property (readonly, getter=isFinished) BOOL finished NS_AVAILABLE(10_5, 2_0); //线程状态,已经取消 @property (readonly, getter=isCancelled) BOOL cancelled NS_AVAILABLE(10_5, 2_0); //取消,仅仅改变线程状态,并不能像exist一样真正的终止线程 - (void)cancel NS_AVAILABLE(10_5, 2_0); //开始 - (void)start NS_AVAILABLE(10_5, 2_0); //线程需要执行的代码,一般写子类的时候会用到 - (void)main NS_AVAILABLE(10_5, 2_0); @end 另外,还有一个NSObject的分类,瞅一眼: @interface NSObject (NSThreadPerformAdditions) //隐式的创建并启动线程,并在指定的线程(主线程或子线程)上执行方法。 - (void)performSelectorOnMainThread:(SEL)aSelector withObject:(nullable id)arg waitUntilDone:(BOOL)wait modes:(nullable NSArray<nsstring *> *)array; - (void)performSelectorOnMainThread:(SEL)aSelector withObject:(nullable id)arg waitUntilDone:(BOOL)wait; - (void)performSelector:(SEL)aSelector onThread:(NSThread *)thr withObject:(nullable id)arg waitUntilDone:(BOOL)wait modes:(nullable NSArray<nsstring *> *)array NS_AVAILABLE(10_5, 2_0); - (void)performSelector:(SEL)aSelector onThread:(NSThread *)thr withObject:(nullable id)arg waitUntilDone:(BOOL)wait NS_AVAILABLE(10_5, 2_0); - (void)performSelectorInBackground:(SEL)aSelector withObject:(nullable id)arg NS_AVAILABLE(10_5, 2_0); @end</nsstring *></nsstring *> |
上面的介绍您还满意吗?小的帮您下载一张图片,您瞧好:
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-(void)creatBigImageView{ self.bigImageView = [[UIImageView alloc] initWithFrame:self.view.bounds]; [self.view addSubview:_bigImageView]; UIButton *startButton = [UIButton buttonWithType:UIButtonTypeSystem]; startButton.frame = CGRectMake(0, 0, self.view.frame.size.width / 2, 50); startButton.backgroundColor = [UIColor grayColor]; [startButton setTitle:@ "开始加载" forState:UIControlStateNormal]; [startButton addTarget:self action:@selector(loadImage) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:startButton]; UIButton *jamButton = [UIButton buttonWithType:UIButtonTypeSystem]; jamButton.frame = CGRectMake(self.view.frame.size.width / 2, 0, self.view.frame.size.width / 2, 50); jamButton.backgroundColor = [UIColor grayColor]; [jamButton setTitle:@ "阻塞测试" forState:UIControlStateNormal]; [jamButton addTarget:self action:@selector(jamTest) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:jamButton]; } -(void)jamTest{ UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@ "线程阻塞" message:@ "" delegate:nil cancelButtonTitle:@ "好" otherButtonTitles:nil, nil]; [alertView show]; } -(void)loadImage{ NSURL *imageUrl = [NSURL URLWithString:@ "http://img5.duitang.com/uploads/item/201206/06/20120606174422_LZSeE.thumb.700_0.jpeg" ]; NSData *imageData = [NSData dataWithContentsOfURL:imageUrl]; [self updateImageData:imageData]; } -(void)updateImageData:(NSData*)imageData{ UIImage *image = [UIImage imageWithData:imageData]; self.bigImageView.image = image; } |
运行结果:
我们可以清楚的看到,主线程阻塞了,用户不可以进行其他操作,你见过这样的应用吗?
所以我们这样改一下:
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-(void)creatBigImageView{ self.bigImageView = [[UIImageView alloc] initWithFrame:self.view.bounds]; [self.view addSubview:_bigImageView]; UIButton *startButton = [UIButton buttonWithType:UIButtonTypeSystem]; startButton.frame = CGRectMake(0, 20, self.view.frame.size.width / 2, 50); startButton.backgroundColor = [UIColor grayColor]; [startButton setTitle:@ "开始加载" forState:UIControlStateNormal]; [startButton addTarget:self action:@selector(loadImageWithMultiThread) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:startButton]; UIButton *jamButton = [UIButton buttonWithType:UIButtonTypeSystem]; jamButton.frame = CGRectMake(self.view.frame.size.width / 2, 20, self.view.frame.size.width / 2, 50); jamButton.backgroundColor = [UIColor grayColor]; [jamButton setTitle:@ "阻塞测试" forState:UIControlStateNormal]; [jamButton addTarget:self action:@selector(jamTest) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:jamButton]; } -(void)jamTest{ UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@ "阻塞测试" message:@ "" delegate:nil cancelButtonTitle:@ "好" otherButtonTitles:nil, nil]; [alertView show]; } -(void)loadImageWithMultiThread{ //方法1:使用对象方法 //NSThread *thread=[[NSThread alloc]initWithTarget:self selector:@selector(loadImage) object:nil]; //??启动一个线程并非就一定立即执行,而是处于就绪状态,当CUP调度时才真正执行 //[thread start]; //方法2:使用类方法 [NSThread detachNewThreadSelector:@selector(loadImage) toTarget:self withObject:nil]; } -(void)loadImage{ NSURL *imageUrl = [NSURL URLWithString:@ "http://img5.duitang.com/uploads/item/201206/06/20120606174422_LZSeE.thumb.700_0.jpeg" ]; NSData *imageData = [NSData dataWithContentsOfURL:imageUrl]; //必须在主线程更新UI,Object:代表调用方法的参数,不过只能传递一个参数(如果有多个参数请使用对象进行封装),waitUntilDone:是否线程任务完成执行 [self performSelectorOnMainThread:@selector(updateImageData:) withObject:imageData waitUntilDone:YES]; //[self updateImageData:imageData]; } -(void)updateImageData:(NSData*)imageData{ UIImage *image = [UIImage imageWithData:imageData]; self.bigImageView.image = image; } |
运行结果:
哎呀,用多线程果然能解决线程阻塞的问题,并且NSThread也比Pthreads好用,仿佛你对精通熟练使用多线程又有了一丝丝曙光。假如我有很多不同类型的任务,每个任务之间还有联系和依赖,你是不是又懵逼了,上面的你是不是觉得又白看了,其实开发中我觉得NSThread用到最多的就是[NSThread currentThread];了。(不要慌,往下看... ...)
转自:http://www.cocoachina.com/ios/20170829/20404.html
标签:url ace 问题 oci 处理 htm 初始化 ref upload
原文地址:http://www.cnblogs.com/huangzs/p/7450793.html