iOS NSOperation學習

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為什麼要用NSOperation？為什麼不用GCD

在我認為NSOperation的優點是可控制性的，可以隨時斷開，暫停線程

 1   NSBlockOperation *operationA = [NSBlockOperation blockOperationWithBlock:^{ 2         for (int i = 0; i<100; i++) { 3             NSLog(@"-operation-下載圖片-%@",[NSThread currentThread]); 4         } 5     }]; 6  7     operationA.completionBlock = ^{ 8         NSLog(@"--開始下載第二張圖片--%@",[NSThread currentThread]); 9     };10 11     NSLog(@"--現在在幹嘛--%@",[NSThread currentThread]);12 13     NSOperationQueue *queue = [[NSOperationQueue alloc] init];14     [queue addOperation:operationA];

 

NSOperation添加線程依賴

NSInvocationOperation *operation1 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(operationA:) object:nil];    NSInvocationOperation *operation2 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(operationB:) object:nil];    NSBlockOperation *operation3 = [NSBlockOperation blockOperationWithBlock:^{        for (int i = 0; i<10; i++) {            NSLog(@"NSBlockoperation3=--1-----%@",[NSThread currentThread]);        }    }];    [operation3 addExecutionBlock:^{        for (int i = 0; i<10; i++) {            NSLog(@"NSBlockoperation3=--2-----%@",[NSThread currentThread]);        }    }];    //添加依賴  不能相互依賴    [operation1 addDependency:operation2];    [operation2 addDependency:operation3];    //建立NSOperationQueue    NSOperationQueue *queue = [[NSOperationQueue alloc] init];    [queue addOperation:operation1];    [queue addOperation:operation2];    [queue addOperation:operation3];

 

iOS NSOperation學習