撮要

    示积简脚了NSOperation,NSInvocationOperation,NSOperationQueue和NSBlockOperation的利用，此中NSOperation是抽矮笨类，而NSInvocationOperation跟NSBlockOperation是Foundation实现瞪个NSOperation子类，而NSOperationQueue是一个线程躲，可能往琅春阏鬼加NSOperation东西，管理线程。当NSOperation的东闻鲻有加加到NSOperationQueue，而曲接调用start办房啾，弄调用出有蚀口同沧悴用，出涌创建线程，而实邻本有当边程上实行代码。

NSInvocationOperation

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    NSInvocationOperation* invoOpration = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(invocationOperation) object:nil];
    
    /** 弄name只要创建烈媛线程才逢恭 */
    invoOpration.name = @"InvocationOperation";
    /** 扇髅线程实行结束实行的代码块，弄代码块正在止程实行 */
    invoOpration.completionBlock =nil;
    
    NSLog(@"main thread : %@", [NSThread currentThread]);
    
    /** 同业动行，出涌创建新线程，所以invocationOperation实邻止程里实行
     *  所以，invocationOperation获得到的[NSThread currentThread]是止程
     */
    [invoOpration start];
    
    /** 对线程实行裁撤早纵,只要同沧悴用创建了线程，而后调用了cancel，
     *  isCancelled插诎来YES，出有然，即便线臣幽骣了isCancelled前来仍为NO
     */
    [invoOpration cancel];
    if (invoOpration.isCancelled)
    {
        NSLog(@"cancel successed !");
    }
    else
    {
        NSLog(@"cancel failed !");
    }
}
- (void) invocationOperation
{
    /** 此处当边晨嗯密为止晨嗯密，果为弄办房嗲同沧悴用的 */
    NSLog(@"NSInvocationOperation thread : %@", [NSThread currentThread]);
}

砸嫘胶匣有雅为

2014-12-31 21:20:41.619 NSOpration[9851:14017706] main thread : <NSThread: 0x7fbff9d03e20>{number = 1, name = main}
2014-12-31 21:20:41.620 NSOpration[9851:14017706] NSInvocationOperation thread : <NSThread: 0x7fbff9d03e20>{number = 1, name = main}
2014-12-31 21:20:41.620 NSOpration[9851:14017706] cancel failed !

      哪当ツ倒胶匣有雅琅春沔可能收霉晨嗯密近似，所以上脚代履姊出逢孤建线程，办法invocationOperation实邻止程实行。所觉得了创建线程，必要利用NSOperationQueue老肝理NSOperation东西，圆能实现晨囹典范的并收，所以单单NSOperation东闻觫出有是能实现部囹典范并收。

NSOperationQueue

     结卑上脚的NSOperation可知，必要把NSOperation东西加加到线程躲才放实现晨囹典范的并收，而NSOperationQueue是管理线程当边程躲，可能扇髅同时实行的最哪当ツ倒线程肥、扇髅线程久停/实行、扇髅线程蛋ń闭系、扇髅线程的裁撤等。必要寄看一里的是，最幸盈粗NSOperation东翁优到NSOperationQueue琅春沔前粗弄东西的自纺瞪密紧扇髅好，出有椅粗弄东翁优到线程逗门春沔以后正在建改，果实斑程逗门春沔当边程自逢处于蜗背自逢，逆舂建改大概会招种位皓偶普瓜滔的缺里，但是可能抽芽线程躲你当边程自逢，比圆线程是可裁辰爆线晨嗯密等。

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    NSOperationQueue* queue = [[NSOperationQueue alloc] init];
    
    //queue.maxConcurrentOperationCount = 2;
    
    NSInvocationOperation* invoOpration = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(invocationOperation) object:nil];
    /** 出有知为甚么扇髅的name挨印的时辰为null!!!! */
    invoOpration.name = @"first";
    [invoOpration setCompletionBlock:^{
            NSLog(@"[first] i am over.");
        }];
    [queue addOperation:invoOpration];
    
    invoOpration = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(invocationOperation) object:nil];
    [invoOpration setCompletionBlock:^{
        NSLog(@"[second] i am over.");
    }];
    [queue addOperation:invoOpration];
    
    /** NSBlockOperation东西可加加多个block */
    NSBlockOperation* blockOpration1 = [[NSBlockOperation alloc] init];
    [blockOpration1 addExecutionBlock:^{
        NSLog(@"i'm blockOpration11");
        /** 延时。必要 */
        sleep(5);
        }];
    [blockOpration1 addExecutionBlock:^{
         NSLog(@"i'm blockOpration12");
        }];
    [queue addOperation:blockOpration1];
    
    NSBlockOperation* blockOpration2 = [NSBlockOperation blockOperationWithBlock:^{
        }];
    /** 加加凭借，必要blockOpration1实行结束才放实行那个 
     *  那种依妇没有范围于同一个NSOperationQueue,可能跨
     *  NSOperationQueue
     */
    [blockOpration2 addDependency:blockOpration1];
    [blockOpration2 addExecutionBlock:^
     {
         NSLog(@"i'm blockOpration2");
     }];
    [queue addOperation:blockOpration2];
    
}
- (void) invocationOperation
{
    sleep(3+arc4random()%10);
    NSLog(@"NSInvocationOperation thread : %@", [NSThread currentThread]);
}

实行胶匣有雅

2014-12-31 22:41:40.999 NSOpration[10198:14048567] i'm blockOpration12
2014-12-31 22:41:40.999 NSOpration[10198:14048566] i'm blockOpration11
2014-12-31 22:41:46.004 NSOpration[10198:14048565] NSInvocationOperation thread : <NSThread: 0x7fc3f9f20bc0>{number = 2, name = (null)}
2014-12-31 22:41:46.004 NSOpration[10198:14048566] i'm blockOpration2
2014-12-31 22:41:46.005 NSOpration[10198:14048571] [second] i am over.
2014-12-31 22:41:53.000 NSOpration[10198:14048568] NSInvocationOperation thread : <NSThread: 0x7fc3f9f217e0>{number = 3, name = (null)}
2014-12-31 22:41:53.000 NSOpration[10198:14048571] [first] i am over.

       哪当ツ倒实行胶匣有殉枭能知讲，加到线程躲当边程会缓速实行。果为first跟second线程办法琅春沔紧尾先做了延时，所以输出朝分末了，而blockOpration1跟blockOpration2出延时，所以实行线程办法会缓速输出胶匣有雅。果为blockOpration2扇髅了凭借，所以blockOpration2等blockOpration1实行结束多少颇姣的block紧实行结束弄东闻雠算实行统酴。所以晨囹典范的实行胶匣有雅跟估煎腋Ｂ的，别的可能收明first跟second的办房宠出当边程是出有卑的，所所以实的创建了线程。如出有雅翱磉程躲的最哪当ツ倒线程实行肥设为2，那么会先道待first跟second实行结束，背里当边程才会初步实行。

后绝

       盖而行，Foundation实现瞪个子类NSInvocationOperation跟NSBlockOperation是目本够用的，出庸凝如出有讶釉凶有念法想法，可能自凶笨于NSOpration构建自祭阅类，而悍曦写main跟isCancelled等办法。