iOS多线程 iOS开发Demo(示例程序)源代码
2013-12-27 21:47
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本系列所有开发文档翻译链接地址:iOS7开发-Apple苹果iPhone开发Xcode官方文档翻译PDF下载地址(2013年12月29日更新版)
iOS程序源代码下载链接:
01.大任务.zip
225.8 KB
//
// ViewController.m
// 01.大任务
//
// Created by apple on 13-12-27.
// Copyright (c) 2013年itcast. All rights reserved.
//
#import"ViewController.h"
@interfaceViewController()
{
//全局的操作队列,由它统一控制所有的NSOperation的操作调度
NSOperationQueue *_queue;
}
@property(weak,nonatomic)IBOutletUIImageView*imageView;
@end
@implementationViewController
/**
无论使用哪种多线程技术都可以使用
[NSThread currentThread]跟踪查看当前执行所在的线程情况。
num = 1表示在主线程上执行的任务
================================================================
1. NSObject多线程技术
1>使用performSelectorInBackground可以开启后台线程,执行selector选择器选择的方法
2>使用performSelectorOnMainThread可以重新回到主线程执行任务,通常用于后台线程更新界面UI时使用
3> [NSThread sleepForTimeInterval:1.0f];
让当前线程休眠,通常在程序开发中,用于模拟耗时操作,以便跟踪不同的并发执行情况!
但是:在程序发布时,千万不要保留此方法!不要把测试中的代码交给客户,否则会造成不好的用户体验。
提示:使用performSelectorInBackground也可以直接修改UI,但是强烈不建议使用。
注意:在使用NSThread或者NSObject的线程方法时,一定要使用自动释放池,否则容易出现内存泄露。
================================================================
2. NSThread的多线程技术
1>类方法直接开启后台线程,并执行选择器方法
detachNewThreadSelector
2>成员方法,在实例化线程对象之后,需要使用start执行选择器方法
initWithTarget
对于NSThread的简单使用,可以用NSObject的performSelectorInBackground替代
同时,在NSThread调用的方法中,同样要使用autoreleasepool进行内存管理,否则容易出现内存泄露。
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
================================================================
3. NSOperation,面向对象的多线程技术
1>使用步骤:
1)实例化操作
a) NSInvocationOperation
b) NSBlockOperation
2)将操作添加到队列NSOperationQueue即可启动多线程执行
2>更新UI使用主线程队列
[NSOpeationQueue mainQueue] addOperation ^{};
3>操作队列的setMaxConcurrentOperationCount
可以设置同时并发的线程数量!
提示:此功能仅有NSOperation有!
4>使用addDependency可以设置任务的执行先后顺序,同时可以跨操作队列指定依赖关系
提示:在指定依赖关系时,注意不要循环依赖,否则不工作。
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
================================================================
4. GCD,C语言
*/
- (void)viewDidLoad
{
[superviewDidLoad];
NSLog(@"%@", [NSThreadcurrentThread]);
//实例化操作队列
_queue= [[NSOperationQueuealloc]init];
}
#pragma mark -操作
//耗时操作演示
- (void)bigDemo
{
//自动释放池
//负责其他线程上的内存管理,在使用NSThread或者NSObject的线程方法时,一定要使用自动释放池
//否则容易出现内存泄露。
@autoreleasepool{
// //模拟网络下载延时
// for (NSInteger i = 0; i < 1000; i++) {
// NSString *str = [NSString stringWithFormat:@"%d", i];
//
// //提示:NSLog是非常耗时的操作!
// NSLog(@"大任务-> %@", str);
// }
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟网络下载延时,睡眠1秒,通常是在开发中测试使用。
[NSThreadsleepForTimeInterval:1.0f];
//强烈不建议直接在后台线程更新界面UI!
//模拟获取到下载的图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//在主线程更新图像
//使用self调用updateImage方法在主线程更新图像
// [self performSelectorOnMainThread:@selector(updateImage:) withObject:image waitUntilDone:YES];
//使用imageView的setImage方法在主线程更新图像
[_imageViewperformSelectorOnMainThread:@selector(setImage:)withObject:imagewaitUntilDone:YES];
// ....
}
}
#pragma mark -更新图像,模拟从网络上下载完图片后,更新界面的操作
- (void)updateImage:(UIImage*)image
{
NSLog(@"更新图像-> %@", [NSThreadcurrentThread]);
_imageView.image= image;
}
#pragma mark - Actions
- (IBAction)bigTask
{
//本方法中的所有代码都是在主线程中执行的
// NSObject多线程技术
NSLog(@"执行前->%@", [NSThreadcurrentThread]);
// performSelectorInBackground是将bigDemo的任务放在后台线程中执行
[selfperformSelectorInBackground:@selector(bigDemo)withObject:nil];
NSLog(@"执行后->%@", [NSThreadcurrentThread]);
// [self bigDemo];
NSLog(@"执行完毕");
}
- (IBAction)smallTask
{
NSString*str =nil;
for(NSIntegeri =0; i <50000; i++) {
str = [NSStringstringWithFormat:@"%d", i];
}
NSLog(@"小任务-> %@", str);
}
#pragma mark NSThread演练
- (IBAction)threadDemo
{
//新建一个线程,调用@selector方法
// [NSThread detachNewThreadSelector:@selector(bigDemo) toTarget:self withObject:nil];
//成员方法
NSThread*thread = [[NSThreadalloc]initWithTarget:selfselector:@selector(bigDemo)object:nil];
//启动start线程
[threadstart];
}
#pragma mark - NSOperation演练
- (void)opAction
{
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟延时
[NSThreadsleepForTimeInterval:1.0f];
//模拟获取到图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//设置图像,在主线程队列中设置
[[NSOperationQueuemainQueue]addOperationWithBlock:^{
_imageView.image= image;
}];
}
#pragma mark invocation
- (IBAction)operationDemo1
{
NSInvocationOperation*op1 = [[NSInvocationOperationalloc]initWithTarget:selfselector:@selector(opAction)object:nil];
//如果使用start,会在当前线程启动操作
// [op1 start];
// 1.一旦将操作添加到操作队列,操作就会启动
[_queueaddOperation:op1];
}
#pragma mark blockOperation
- (IBAction)operationDemo2
{
//用block的最大好处,可以将一组相关的操作,顺序写在一起,便于调试以及代码编写
[_queueaddOperationWithBlock:^{
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟延时
[NSThreadsleepForTimeInterval:1.0f];
//模拟获取到图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//设置图像,在主线程队列中设置
[[NSOperationQueuemainQueue]addOperationWithBlock:^{
_imageView.image= image;
}];
}];
}
#pragma mark模仿下载网络图像
- (IBAction)operationDemo3:(id)sender
{
// 1.下载
NSBlockOperation*op1 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"下载%@", [NSThreadcurrentThread]);
}];
// 2.滤镜
NSBlockOperation*op2 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"滤镜%@", [NSThreadcurrentThread]);
}];
// 3.显示
NSBlockOperation*op3 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"更新UI %@", [NSThreadcurrentThread]);
}];
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
//添加操作之间的依赖关系,所谓“依赖”关系,就是等待前一个任务完成后,后一个任务才能启动
//依赖关系可以跨线程队列实现
//提示:在指定依赖关系时,注意不要循环依赖,否则不工作。
[op2addDependency:op1];
[op3addDependency:op2];
// [op1 addDependency:op3];
[_queueaddOperation:op1];
[_queueaddOperation:op2];
[[NSOperationQueuemainQueue]addOperation:op3];
}
#pragma mark限制线程数量
- (IBAction)operationDemo4
{
//控制同时最大并发的线程数量
[_queuesetMaxConcurrentOperationCount:2];
for(NSIntegeri =0; i <200; i++) {
NSBlockOperation*op = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"%@", [NSThreadcurrentThread]);
}];
[_queueaddOperation:op];
}
}
#pragma mark - GCD演练
- (IBAction)gcdDemo1
{
/**
GCD就是为了在“多核”上使用多线程技术
1>要使用GCD,所有的方法都是dispatch开头的
2>名词解释
global 全局
queue 队列
async 异步
sync 同步
3>要执行异步的任务,就在全局队列中执行即可
dispatch_async异步执行控制不住先后顺序
4>关于GCD的队列
全局队列 dispatch_get_global_queue
参数:优先级DISPATCH_QUEUE_PRIORITY_DEFAULT
始终是0
串行队列
主队列
5>异步和同步于方法名无关,与运行所在的队列有关!
提示:要熟悉队列于同步、异步的运行节奏,一定需要自己编写代码测试!
同步主要用来控制方法的被调用的顺序
*/
// 1.队列
dispatch_queue_t queue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);
// 2.将任务异步(并发)执行
dispatch_async(queue, ^{
NSLog(@"a->%@", [NSThreadcurrentThread]);
});
dispatch_async(queue, ^{
NSLog(@"b->%@", [NSThreadcurrentThread]);
});
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"main - > %@", [NSThreadcurrentThread]);
});
}
@end
执行前-><NSThread: 0x764bcb0>{name = (null), num = 1}
执行后-><NSThread: 0x764bcb0>{name = (null), num = 1}
执行完毕bigDemo<NSThread: 0x768d8f0>{name = (null), num = 3}
执行前-><NSThread: 0x764bcb0>{name = (null), num = 1}
bigDemo<NSThread: 0x755c8d0>{name = (null), num = 4}
执行后-><NSThread: 0x764bcb0>{name = (null), num = 1}
执行完毕
performSelectorInBackground:withObject:该方法会使方法在后台运行,并负责为其分配线程号,一个线程3结束后,不会被回收.再次调用performSelectorInBackground:withObject:会分配4而非3
2013-12-27 19:06:01.311 1226-01-大任务[4742:51b] bigDemo<NSThread: 0x753d5d0>{name = (null), num = 3}
2013-12-27 19:06:06.266 1226-01-大任务[4742:440b] bigDemo<NSThread: 0x753f1f0>{name = (null), num = 4}
2013-12-27 19:06:07.060 1226-01-大任务[4742:4503] bigDemo<NSThread: 0x7540cb0>{name = (null), num = 5}
2013-12-27 19:06:07.659 1226-01-大任务[4742:440f] bigDemo<NSThread: 0x753d9f0>{name = (null), num = 6}
2013-12-27 19:06:08.318 1226-01-大任务[4742:4507] bigDemo<NSThread: 0x7540cb0>{name = (null), num = 7}
initWithTarget:selector:object:方法能为方法分配线程
2013-12-27 19:24:16.153 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:18.755 1226-01-大任务[4858:4203] <NSThread: 0x768acf0>{name = (null), num = 4}
2013-12-27 19:24:19.245 1226-01-大任务[4858:1103] <NSThread: 0x768aa40>{name = (null), num = 5}
2013-12-27 19:24:19.724 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:20.205 1226-01-大任务[4858:4703] <NSThread: 0x768b7e0>{name = (null), num = 6}
addOperation:方法能为方法分配线程
2013-12-27 19:24:16.153 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:18.755 1226-01-大任务[4858:4203] <NSThread: 0x768acf0>{name = (null), num = 4}
2013-12-27 19:24:19.245 1226-01-大任务[4858:1103] <NSThread: 0x768aa40>{name = (null), num = 5}
2013-12-27 19:24:19.724 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:20.205 1226-01-大任务[4858:4703] <NSThread: 0x768b7e0>{name = (null), num = 6}
operationDemo1方法与operationDemo2方法效果一致
//用block的最大好处,可以将一组相关的操作,顺序写在一起,便于调试以及代码编写
黄色部分是时间,结果发现:相同的时间只可能出现两次.
2013-12-27 20:00:58.088 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.088 1226-01-大任务[5127:1103] <NSThread: 0x7667740>{name = (null), num = 3}
2013-12-27 20:00:58.092 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.093 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.096 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.096 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.099 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.100 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.101 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.102 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.105 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.106 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.107 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.107 1226-01-大任务[5127:4107] <NSThread: 0x7530f50>{name = (null), num = 6}
2013-12-27 20:00:58.125 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.126 1226-01-大任务[5127:4107] <NSThread: 0x7530f50>{name = (null), num = 6}
2013-12-27 20:00:58.129 1226-01-大任务[5127:1103] <NSThread: 0x7667740>{name = (null), num = 3}
2013-12-27 20:00:58.129 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.132 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
setMaxConcurrentOperationCount 方法能控制同时最大并发的线程数量
——————————————————— <第⓵次运行gcd>———————————————————————
——————————————————— <第⓵点击gcd按钮>———————————————————————
2013-12-27 20:23:49.987 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:49.988 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:49.987 1226-01-大任务[5270:1903] ###################-><NSThread: 0x76bfb20>{name = (null), num = 4}
——————————————————— <第⓶点击gcd按钮>———————————————————————
2013-12-27 20:23:54.336 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:54.337 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:54.337 1226-01-大任务[5270:1103] ###################-><NSThread: 0x75848f0>{name = (null), num = 3}
——————————————————— <第⓷点击gcd按钮>———————————————————————
2013-12-27 20:23:59.435 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:59.436 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:59.437 1226-01-大任务[5270:1103] ###################-><NSThread: 0x75848f0>{name = (null), num = 3}
——————————————————— <第⓶次运行gcd>———————————————————————
——————————————————— <第⓵点击gcd按钮>———————————————————————
2013-12-27 20:24:49.950 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:49.950 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:49.949 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
——————————————————— <第⓶点击gcd按钮>———————————————————————
2013-12-27 20:24:53.798 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:53.798 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:53.798 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
——————————————————— <第⓷点击gcd按钮>———————————————————————
2013-12-27 20:24:55.320 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:55.321 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:55.321 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
要执行异步的任务,就在全局队列dispatch_get_global_queue中执行即可
dispatch_async异步执行控制不住先后顺序
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
https://www.evernote.com/shard/s227/sh/911b8ec7-498f-4c93-b180-6713e5e03931/382ccb2b15dd2630ddd9756e48fc1446
01.大任务.zip
225.8 KB
//
// ViewController.m
// 01.大任务
//
// Created by apple on 13-12-27.
// Copyright (c) 2013年itcast. All rights reserved.
//
#import"ViewController.h"
@interfaceViewController()
{
//全局的操作队列,由它统一控制所有的NSOperation的操作调度
NSOperationQueue *_queue;
}
@property(weak,nonatomic)IBOutletUIImageView*imageView;
@end
@implementationViewController
/**
无论使用哪种多线程技术都可以使用
[NSThread currentThread]跟踪查看当前执行所在的线程情况。
num = 1表示在主线程上执行的任务
================================================================
1. NSObject多线程技术
1>使用performSelectorInBackground可以开启后台线程,执行selector选择器选择的方法
2>使用performSelectorOnMainThread可以重新回到主线程执行任务,通常用于后台线程更新界面UI时使用
3> [NSThread sleepForTimeInterval:1.0f];
让当前线程休眠,通常在程序开发中,用于模拟耗时操作,以便跟踪不同的并发执行情况!
但是:在程序发布时,千万不要保留此方法!不要把测试中的代码交给客户,否则会造成不好的用户体验。
提示:使用performSelectorInBackground也可以直接修改UI,但是强烈不建议使用。
注意:在使用NSThread或者NSObject的线程方法时,一定要使用自动释放池,否则容易出现内存泄露。
================================================================
2. NSThread的多线程技术
1>类方法直接开启后台线程,并执行选择器方法
detachNewThreadSelector
2>成员方法,在实例化线程对象之后,需要使用start执行选择器方法
initWithTarget
对于NSThread的简单使用,可以用NSObject的performSelectorInBackground替代
同时,在NSThread调用的方法中,同样要使用autoreleasepool进行内存管理,否则容易出现内存泄露。
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
================================================================
3. NSOperation,面向对象的多线程技术
1>使用步骤:
1)实例化操作
a) NSInvocationOperation
b) NSBlockOperation
2)将操作添加到队列NSOperationQueue即可启动多线程执行
2>更新UI使用主线程队列
[NSOpeationQueue mainQueue] addOperation ^{};
3>操作队列的setMaxConcurrentOperationCount
可以设置同时并发的线程数量!
提示:此功能仅有NSOperation有!
4>使用addDependency可以设置任务的执行先后顺序,同时可以跨操作队列指定依赖关系
提示:在指定依赖关系时,注意不要循环依赖,否则不工作。
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
================================================================
4. GCD,C语言
*/
- (void)viewDidLoad
{
[superviewDidLoad];
NSLog(@"%@", [NSThreadcurrentThread]);
//实例化操作队列
_queue= [[NSOperationQueuealloc]init];
}
#pragma mark -操作
//耗时操作演示
- (void)bigDemo
{
//自动释放池
//负责其他线程上的内存管理,在使用NSThread或者NSObject的线程方法时,一定要使用自动释放池
//否则容易出现内存泄露。
@autoreleasepool{
// //模拟网络下载延时
// for (NSInteger i = 0; i < 1000; i++) {
// NSString *str = [NSString stringWithFormat:@"%d", i];
//
// //提示:NSLog是非常耗时的操作!
// NSLog(@"大任务-> %@", str);
// }
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟网络下载延时,睡眠1秒,通常是在开发中测试使用。
[NSThreadsleepForTimeInterval:1.0f];
//强烈不建议直接在后台线程更新界面UI!
//模拟获取到下载的图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//在主线程更新图像
//使用self调用updateImage方法在主线程更新图像
// [self performSelectorOnMainThread:@selector(updateImage:) withObject:image waitUntilDone:YES];
//使用imageView的setImage方法在主线程更新图像
[_imageViewperformSelectorOnMainThread:@selector(setImage:)withObject:imagewaitUntilDone:YES];
// ....
}
}
#pragma mark -更新图像,模拟从网络上下载完图片后,更新界面的操作
- (void)updateImage:(UIImage*)image
{
NSLog(@"更新图像-> %@", [NSThreadcurrentThread]);
_imageView.image= image;
}
#pragma mark - Actions
- (IBAction)bigTask
{
//本方法中的所有代码都是在主线程中执行的
// NSObject多线程技术
NSLog(@"执行前->%@", [NSThreadcurrentThread]);
// performSelectorInBackground是将bigDemo的任务放在后台线程中执行
[selfperformSelectorInBackground:@selector(bigDemo)withObject:nil];
NSLog(@"执行后->%@", [NSThreadcurrentThread]);
// [self bigDemo];
NSLog(@"执行完毕");
}
- (IBAction)smallTask
{
NSString*str =nil;
for(NSIntegeri =0; i <50000; i++) {
str = [NSStringstringWithFormat:@"%d", i];
}
NSLog(@"小任务-> %@", str);
}
#pragma mark NSThread演练
- (IBAction)threadDemo
{
//新建一个线程,调用@selector方法
// [NSThread detachNewThreadSelector:@selector(bigDemo) toTarget:self withObject:nil];
//成员方法
NSThread*thread = [[NSThreadalloc]initWithTarget:selfselector:@selector(bigDemo)object:nil];
//启动start线程
[threadstart];
}
#pragma mark - NSOperation演练
- (void)opAction
{
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟延时
[NSThreadsleepForTimeInterval:1.0f];
//模拟获取到图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//设置图像,在主线程队列中设置
[[NSOperationQueuemainQueue]addOperationWithBlock:^{
_imageView.image= image;
}];
}
#pragma mark invocation
- (IBAction)operationDemo1
{
NSInvocationOperation*op1 = [[NSInvocationOperationalloc]initWithTarget:selfselector:@selector(opAction)object:nil];
//如果使用start,会在当前线程启动操作
// [op1 start];
// 1.一旦将操作添加到操作队列,操作就会启动
[_queueaddOperation:op1];
}
#pragma mark blockOperation
- (IBAction)operationDemo2
{
//用block的最大好处,可以将一组相关的操作,顺序写在一起,便于调试以及代码编写
[_queueaddOperationWithBlock:^{
NSLog(@"%@", [NSThreadcurrentThread]);
//模拟延时
[NSThreadsleepForTimeInterval:1.0f];
//模拟获取到图像
UIImage*image = [UIImageimageNamed:@"头像1"];
//设置图像,在主线程队列中设置
[[NSOperationQueuemainQueue]addOperationWithBlock:^{
_imageView.image= image;
}];
}];
}
#pragma mark模仿下载网络图像
- (IBAction)operationDemo3:(id)sender
{
// 1.下载
NSBlockOperation*op1 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"下载%@", [NSThreadcurrentThread]);
}];
// 2.滤镜
NSBlockOperation*op2 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"滤镜%@", [NSThreadcurrentThread]);
}];
// 3.显示
NSBlockOperation*op3 = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"更新UI %@", [NSThreadcurrentThread]);
}];
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
//添加操作之间的依赖关系,所谓“依赖”关系,就是等待前一个任务完成后,后一个任务才能启动
//依赖关系可以跨线程队列实现
//提示:在指定依赖关系时,注意不要循环依赖,否则不工作。
[op2addDependency:op1];
[op3addDependency:op2];
// [op1 addDependency:op3];
[_queueaddOperation:op1];
[_queueaddOperation:op2];
[[NSOperationQueuemainQueue]addOperation:op3];
}
#pragma mark限制线程数量
- (IBAction)operationDemo4
{
//控制同时最大并发的线程数量
[_queuesetMaxConcurrentOperationCount:2];
for(NSIntegeri =0; i <200; i++) {
NSBlockOperation*op = [NSBlockOperationblockOperationWithBlock:^{
NSLog(@"%@", [NSThreadcurrentThread]);
}];
[_queueaddOperation:op];
}
}
#pragma mark - GCD演练
- (IBAction)gcdDemo1
{
/**
GCD就是为了在“多核”上使用多线程技术
1>要使用GCD,所有的方法都是dispatch开头的
2>名词解释
global 全局
queue 队列
async 异步
sync 同步
3>要执行异步的任务,就在全局队列中执行即可
dispatch_async异步执行控制不住先后顺序
4>关于GCD的队列
全局队列 dispatch_get_global_queue
参数:优先级DISPATCH_QUEUE_PRIORITY_DEFAULT
始终是0
串行队列
主队列
5>异步和同步于方法名无关,与运行所在的队列有关!
提示:要熟悉队列于同步、异步的运行节奏,一定需要自己编写代码测试!
同步主要用来控制方法的被调用的顺序
*/
// 1.队列
dispatch_queue_t queue =dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,0);
// 2.将任务异步(并发)执行
dispatch_async(queue, ^{
NSLog(@"a->%@", [NSThreadcurrentThread]);
});
dispatch_async(queue, ^{
NSLog(@"b->%@", [NSThreadcurrentThread]);
});
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"main - > %@", [NSThreadcurrentThread]);
});
}
@end
连续点击两次大任务按钮,运行结果 |
执行后-><NSThread: 0x764bcb0>{name = (null), num = 1}
执行完毕bigDemo<NSThread: 0x768d8f0>{name = (null), num = 3}
执行前-><NSThread: 0x764bcb0>{name = (null), num = 1}
bigDemo<NSThread: 0x755c8d0>{name = (null), num = 4}
执行后-><NSThread: 0x764bcb0>{name = (null), num = 1}
执行完毕
结论 |
连续点击NSThread,运行结果 |
2013-12-27 19:06:06.266 1226-01-大任务[4742:440b] bigDemo<NSThread: 0x753f1f0>{name = (null), num = 4}
2013-12-27 19:06:07.060 1226-01-大任务[4742:4503] bigDemo<NSThread: 0x7540cb0>{name = (null), num = 5}
2013-12-27 19:06:07.659 1226-01-大任务[4742:440f] bigDemo<NSThread: 0x753d9f0>{name = (null), num = 6}
2013-12-27 19:06:08.318 1226-01-大任务[4742:4507] bigDemo<NSThread: 0x7540cb0>{name = (null), num = 7}
结论 |
连续点击NSOperation按钮,运行结果 |
2013-12-27 19:24:18.755 1226-01-大任务[4858:4203] <NSThread: 0x768acf0>{name = (null), num = 4}
2013-12-27 19:24:19.245 1226-01-大任务[4858:1103] <NSThread: 0x768aa40>{name = (null), num = 5}
2013-12-27 19:24:19.724 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:20.205 1226-01-大任务[4858:4703] <NSThread: 0x768b7e0>{name = (null), num = 6}
结论 |
连续点击NSBlockOperation按钮,运行结果 |
2013-12-27 19:24:18.755 1226-01-大任务[4858:4203] <NSThread: 0x768acf0>{name = (null), num = 4}
2013-12-27 19:24:19.245 1226-01-大任务[4858:1103] <NSThread: 0x768aa40>{name = (null), num = 5}
2013-12-27 19:24:19.724 1226-01-大任务[4858:1703] <NSThread: 0x7686610>{name = (null), num = 3}
2013-12-27 19:24:20.205 1226-01-大任务[4858:4703] <NSThread: 0x768b7e0>{name = (null), num = 6}
结论 |
//用block的最大好处,可以将一组相关的操作,顺序写在一起,便于调试以及代码编写
限制并发线程数,运行结果 |
2013-12-27 20:00:58.088 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.088 1226-01-大任务[5127:1103] <NSThread: 0x7667740>{name = (null), num = 3}
2013-12-27 20:00:58.092 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.093 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.096 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.096 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.099 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.100 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.101 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.102 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.105 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.106 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.107 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
2013-12-27 20:00:58.107 1226-01-大任务[5127:4107] <NSThread: 0x7530f50>{name = (null), num = 6}
2013-12-27 20:00:58.125 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.126 1226-01-大任务[5127:4107] <NSThread: 0x7530f50>{name = (null), num = 6}
2013-12-27 20:00:58.129 1226-01-大任务[5127:1103] <NSThread: 0x7667740>{name = (null), num = 3}
2013-12-27 20:00:58.129 1226-01-大任务[5127:1703] <NSThread: 0x754ad60>{name = (null), num = 4}
2013-12-27 20:00:58.132 1226-01-大任务[5127:517] <NSThread: 0x752def0>{name = (null), num = 5}
结论 |
运行两次程序,并在每次运行时连续点击gcd按钮三次,运行结果 |
——————————————————— <第⓵点击gcd按钮>———————————————————————
2013-12-27 20:23:49.987 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:49.988 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:49.987 1226-01-大任务[5270:1903] ###################-><NSThread: 0x76bfb20>{name = (null), num = 4}
——————————————————— <第⓶点击gcd按钮>———————————————————————
2013-12-27 20:23:54.336 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:54.337 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:54.337 1226-01-大任务[5270:1103] ###################-><NSThread: 0x75848f0>{name = (null), num = 3}
——————————————————— <第⓷点击gcd按钮>———————————————————————
2013-12-27 20:23:59.435 1226-01-大任务[5270:907] #########main - ><NSThread: 0x75652f0>{name = (null), num = 1}
2013-12-27 20:23:59.436 1226-01-大任务[5270:1103] ###########################-><NSThread: 0x75848f0>{name = (null), num = 3}
2013-12-27 20:23:59.437 1226-01-大任务[5270:1103] ###################-><NSThread: 0x75848f0>{name = (null), num = 3}
——————————————————— <第⓶次运行gcd>———————————————————————
——————————————————— <第⓵点击gcd按钮>———————————————————————
2013-12-27 20:24:49.950 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:49.950 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:49.949 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
——————————————————— <第⓶点击gcd按钮>———————————————————————
2013-12-27 20:24:53.798 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:53.798 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:53.798 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
——————————————————— <第⓷点击gcd按钮>———————————————————————
2013-12-27 20:24:55.320 1226-01-大任务[5288:907] #########main - ><NSThread: 0x764b3e0>{name = (null), num = 1}
2013-12-27 20:24:55.321 1226-01-大任务[5288:1a03] ###################-><NSThread: 0x76911d0>{name = (null), num = 4}
2013-12-27 20:24:55.321 1226-01-大任务[5288:1103] ###########################-><NSThread: 0x7687e20>{name = (null), num = 3}
结论 |
dispatch_async异步执行控制不住先后顺序
//转载请注明出处--本文永久链接:http://www.cnblogs.com/ChenYilong/p/3494810.html
https://www.evernote.com/shard/s227/sh/911b8ec7-498f-4c93-b180-6713e5e03931/382ccb2b15dd2630ddd9756e48fc1446
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