NSOperation 相关函数

- (void)testWithType:(NSInteger)type{
    for (int i=0; i<10; i++) {
        NSLog(@"operation%zd = %d - %@",type,i,[NSThread currentThread]);
    }
}

1. ** NSInvocationOperation**

    //默认是主线程  搭配NSOperationQueue实现多线程
    NSInvocationOperation *invocationOperation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(testWithType:) object:@(1)];
    [invocationOperation start];

2. ** NSBlockOperation**

    //默认是主线程  搭配NSOperationQueue实现多线程
    NSBlockOperation *blockOperation = [NSBlockOperation blockOperationWithBlock:^{
        for (int i=0; i<3; i++) {
            NSLog(@"主线程 = %d - %@",i,[NSThread currentThread]);
        }
    }];
    //添加任务会自动加入到多线程
    [blockOperation addExecutionBlock:^{
        for (int i=0; i<3; i++) {
            NSLog(@"可以实现多线程 = %d - %@",i,[NSThread currentThread]);
        }
    }];
    [blockOperation start];

3. 线程依赖

    //线程依赖
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    NSBlockOperation *operation1 = [NSBlockOperation blockOperationWithBlock:^{
        [self testWithType:1];//多线程
    }];
    NSBlockOperation *operation2 = [NSBlockOperation blockOperationWithBlock:^{
        [self testWithType:2];//多线程
    }];
    NSBlockOperation *operation3 = [NSBlockOperation blockOperationWithBlock:^{
        [self testWithType:3];//多线程
    }];
    NSBlockOperation *operationAfter = [NSBlockOperation blockOperationWithBlock:^{
        for (int i=0; i<10; i++) {
            NSLog(@"operationAfter = %d - %@",i,[NSThread currentThread]);
        }
    }];
    [operationAfter addDependency:operation1];
    [operationAfter addDependency:operation2];
    [operationAfter addDependency:operation3];
    //operationAfter 依赖于 operation1，operation2，operation3
    [queue addOperation:operation1];
    [queue addOperation:operation2];
    [queue addOperation:operation3];
    [queue addOperation:operationAfter];

3. 线程并发控制

    // 创建队列，默认并发
    NSOperationQueue *queue = [[NSOperationQueue alloc] init];
    // 最大并发数:  =1为串行; >1为并行;
    queue.maxConcurrentOperationCount = 1;
    // 添加操作到队列
    [queue addOperationWithBlock:^{
        for (int i=0; i<10; i++) {
            NSLog(@"addOperationWithBlock1 = %d - %@",i,[NSThread currentThread]);
        }
    }];
    [queue addOperationWithBlock:^{
        for (int i=0; i<10; i++) {
            NSLog(@"addOperationWithBlock2 = %d - %@",i,[NSThread currentThread]);
        }
    }];
```[图片上传失败...(image-355539-1635760294185)]