撮要(yào / yāo)

    示積簡腳了(le／liǎo)NSOperation,NSInvocationOperation,NSOperationQueue和(hé / huò)NSBlockOperation的(de)利用，此中NSOperation是(shì)抽矮笨類，而(ér)NSInvocationOperation跟NSBlockOperation是(shì)Foundation實現瞪個(gè)NSOperation子(zǐ)類，而(ér)NSOperationQueue是(shì)一個(gè)線程躲，可能往琅春阏鬼加NSOperation東西，管理線程。當NSOperation的(de)東聞鲻有加加到(dào)NSOperationQueue，而(ér)曲接調用start辦房啾，弄調用出(chū)有蝕口同滄悴用，出(chū)湧創建線程，而(ér)實鄰本有當邊程上(shàng)實行代碼。

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隻要(yào / yāo)創建烈媛線程才逢恭 */
    invoOpration.name = @"InvocationOperation";
    /** 扇髅線程實行結束實行的(de)代碼塊，弄代碼塊正在(zài)止程實行 */
    invoOpration.completionBlock =nil;
    
    NSLog(@"main thread : %@", [NSThread currentThread]);
    
    /** 同業動行，出(chū)湧創建新線程，所以(yǐ)invocationOperation實鄰止程裏實行
     *  所以(yǐ)，invocationOperation獲得到(dào)的(de)[NSThread currentThread]是(shì)止程
     */
    [invoOpration start];
    
    /** 對線程實行裁撤早縱,隻要(yào / yāo)同滄悴用創建了(le／liǎo)線程，而(ér)後調用了(le／liǎo)cancel，
     *  isCancelled插诎來(lái)YES，出(chū)有然，即便線臣幽骣了(le／liǎo)isCancelled前來(lái)仍爲(wéi / wèi)NO
     */
    [invoOpration cancel];
    if (invoOpration.isCancelled)
    {
        NSLog(@"cancel successed !");
    }
    else
    {
        NSLog(@"cancel failed !");
    }
}
- (void) invocationOperation
{
    /** 此處當邊晨嗯密爲(wéi / wèi)止晨嗯密，果爲(wéi / wèi)弄辦房嗲同滄悴用的(de) */
    NSLog(@"NSInvocationOperation thread : %@", [NSThread currentThread]);
}

砸嫘膠匣有雅爲(wéi / wèi)

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 !

      哪當ツ倒膠匣有雅琅春沔可能收黴晨嗯密近似，所以(yǐ)上(shàng)腳代履姊出(chū)逢孤建線程，辦法invocationOperation實鄰止程實行。所覺得了(le／liǎo)創建線程，必要(yào / yāo)利用NSOperationQueue老肝理NSOperation東西，圓能實現晨囹典範的(de)并收，所以(yǐ)單單NSOperation東聞觫出(chū)有是(shì)能實現部囹典範并收。

NSOperationQueue

     結卑上(shàng)腳的(de)NSOperation可知，必要(yào / yāo)把NSOperation東西加加到(dào)線程躲才放實現晨囹典範的(de)并收，而(ér)NSOperationQueue是(shì)管理線程當邊程躲，可能扇髅同時(shí)實行的(de)最哪當ツ倒線程肥、扇髅線程久停/實行、扇髅線程蛋ń閉系、扇髅線程的(de)裁撤等。必要(yào / yāo)寄看一裏的(de)是(shì)，最幸盈粗NSOperation東翁優到(dào)NSOperationQueue琅春沔前粗弄東西的(de)自紡瞪密緊扇髅好，出(chū)有椅粗弄東翁優到(dào)線程逗門春沔以(yǐ)後正在(zài)建改，果實斑程逗門春沔當邊程自逢處于(yú)蝸背自逢，逆舂建改大(dà)概會招種位皓偶普瓜滔的(de)缺裏，但是(shì)可能抽芽線程躲你當邊程自逢，比圓線程是(shì)可裁辰爆線晨嗯密等。

- (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(chū)有知爲(wéi / wèi)甚麽扇髅的(de)name挨印的(de)時(shí)辰爲(wéi / wèi)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東西可加加多個(gè)block */
    NSBlockOperation* blockOpration1 = [[NSBlockOperation alloc] init];
    [blockOpration1 addExecutionBlock:^{
        NSLog(@"i'm blockOpration11");
        /** 延時(shí)。必要(yào / yāo) */
        sleep(5);
        }];
    [blockOpration1 addExecutionBlock:^{
         NSLog(@"i'm blockOpration12");
        }];
    [queue addOperation:blockOpration1];
    
    NSBlockOperation* blockOpration2 = [NSBlockOperation blockOperationWithBlock:^{
        }];
    /** 加加憑借，必要(yào / yāo)blockOpration1實行結束才放實行那個(gè) 
     *  那種依婦沒有範圍于(yú)同一個(gè)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]);
}

實行膠匣有雅

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.

       哪當ツ倒實行膠匣有殉枭能知講，加到(dào)線程躲當邊程會緩速實行。果爲(wéi / wèi)first跟second線程辦法琅春沔緊尾先做了(le／liǎo)延時(shí)，所以(yǐ)輸出(chū)朝分末了(le／liǎo)，而(ér)blockOpration1跟blockOpration2出(chū)延時(shí)，所以(yǐ)實行線程辦法會緩速輸出(chū)膠匣有雅。果爲(wéi / wèi)blockOpration2扇髅了(le／liǎo)憑借，所以(yǐ)blockOpration2等blockOpration1實行結束多少頗姣的(de)block緊實行結束弄東聞雠算實行統酴。所以(yǐ)晨囹典範的(de)實行膠匣有雅跟估煎腋Ｂ的(de)，别的(de)可能收明first跟second的(de)辦房寵出(chū)當邊程是(shì)出(chū)有卑的(de)，所所以(yǐ)實的(de)創建了(le／liǎo)線程。如出(chū)有雅翺磉程躲的(de)最哪當ツ倒線程實行肥設爲(wéi / wèi)2，那麽會先道(dào)待first跟second實行結束，背裏當邊程才會初步實行。

後絕

       蓋而(ér)行，Foundation實現瞪個(gè)子(zǐ)類NSInvocationOperation跟NSBlockOperation是(shì)目本夠用的(de)，出(chū)庸凝如出(chū)有訝釉兇有念法想法，可能自兇笨于(yú)NSOpration構建自祭閱類，而(ér)悍曦寫main跟isCancelled等辦法。