NSOperation和NSOperationQueue的一些基本操作
当初学习多线程这一块的时候,时间比较匆忙,没有细细考虑,而今重新学一次,算是复习和总结吧。
1 #import "ViewController.h" 2 3 @interface ViewController () 4 5 @end 6 7 @implementation ViewController 8 9 /* 10 通过调用[self invocationOperation]的log,可以发现,在不加入queue的情况下,默认是在主线程中同步执行操作的 11 12 而通过调用[self blockOperation]的log,可以发现,在不加入queue的情况下,同一个block里的任务是,默认是在主线程中同步执行操作的。但是,如果有多个block操作,会是并发、异步执行的 13 14 NSBlockOperation 可以设置监听,调用[self opeationListen] 在完成任务后,可以设置完成这个任务想要执行的操作 15 16 调用[self operationQueue]的log,可以发现,在不设置依赖的情况下,任务是并发、异步执行的 17 18 而设置依赖的情况下,设置了依赖的任务按照所设定的顺序调用,而没有设置的,则是并发、异步执行 19 */ 20 - (void)viewDidLoad { 21 [super viewDidLoad]; 22 23 [self opeationListen]; 24 } 25 26 - (void)invocationOperation 27 { 28 NSInvocationOperation *invocation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(downLoadImage) object:nil]; 29 [invocation start]; 30 } 31 32 - (void)blockOperation 33 { 34 NSBlockOperation *blockOperation = [[NSBlockOperation alloc] init]; 35 36 [blockOperation addExecutionBlock:^{ 37 for (int i = 0; i<10; i++) { 38 NSLog(@"blockOperation------下载图片1---%@", [NSThread currentThread]); 39 [NSThread sleepForTimeInterval:0.1]; 40 } 41 }]; 42 43 [blockOperation addExecutionBlock:^{ 44 NSLog(@"blockOperation__2 --- %@",[NSThread currentThread]); 45 }]; 46 47 [blockOperation addExecutionBlock:^{ 48 NSLog(@"blockOperation__3 --- %@",[NSThread currentThread]); 49 }]; 50 51 [blockOperation start]; 52 } 53 54 - (void)opeationListen 55 { 56 NSBlockOperation *blockOperation = [NSBlockOperation blockOperationWithBlock:^{ 57 for (int i = 0; i<10; i++) { 58 NSLog(@"opeationListen------下载图片---%@", [NSThread currentThread]); 59 } 60 }]; 61 62 blockOperation.completionBlock = ^{ 63 // ...下载完图片后想做事情 64 NSLog(@"NSBlockOperation------下载图片完毕---%@", [NSThread currentThread]); 65 }; 66 67 [blockOperation start]; 68 } 69 70 - (void)downLoadImage 71 { 72 for (int i = 0; i < 10; i++) { 73 NSLog(@"downLoadImage----正在下载----image---%@",[NSThread currentThread]); 74 [NSThread sleepForTimeInterval:0.2]; 75 } 76 } 77 78 - (void)run 79 { 80 for (int i = 0; i<10; i++) { 81 NSLog(@"run---正在跑步-----%@", [NSThread currentThread]); 82 [NSThread sleepForTimeInterval:0.2]; 83 } 84 } 85 - (void)operationQueue 86 { 87 NSInvocationOperation *invocationOperation_1 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(downLoadImage) object:nil]; 88 89 NSInvocationOperation *invocationOperation_2 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(run) object:nil]; 90 91 NSBlockOperation *blockOperation_1 = [NSBlockOperation blockOperationWithBlock:^{ 92 for (int i = 0; i < 10; i++) { 93 NSLog(@"blockOperation_1------下载图片---%@", [NSThread currentThread]); 94 [NSThread sleepForTimeInterval:0.1]; 95 } 96 }]; 97 98 NSBlockOperation *blockOperation_2 = [NSBlockOperation blockOperationWithBlock:^{ 99 for (int i = 0; i < 10; i++) { 100 NSLog(@"blockOperation_2------下载视频---%@", [NSThread currentThread]); 101 [NSThread sleepForTimeInterval:0.1]; 102 } 103 }]; 104 105 //设置依赖 106 [blockOperation_2 addDependency:blockOperation_1]; 107 108 NSOperationQueue *queue = [[NSOperationQueue alloc] init]; 109 110 //设置最大并发数(一般设置为2~~3个) 111 queue.maxConcurrentOperationCount = 3; 112 113 [queue addOperations:@[invocationOperation_1, invocationOperation_2, blockOperation_1, blockOperation_2] waitUntilFinished:NO]; 114 } 115 @end
朋友们,虽然这个世界日益浮躁起来,只要能够为了当时纯粹的梦想和感动坚持努力下去,不管其它人怎么样,我们也能够保持自己的本色走下去。