最大并发数

最大并发数

// 1.创建一个队列（非主队列）

    NSOperationQueue *queue = [[NSOperationQueuealloc]init];
   
    // 2.设置最大并发(最多同时并发执行3个任务)
    queue.maxConcurrentOperationCount= 3;
   
    // 3.添加操作到队列中（自动异步执行任务，并发）
    NSBlockOperation *operation1 = [NSBlockOperationblockOperationWithBlock:^{
        NSLog(@"下载图片1---%@", [NSThread currentThread]);
    }];
    NSBlockOperation *operation2 = [NSBlockOperationblockOperationWithBlock:^{
        NSLog(@"下载图片2---%@", [NSThread currentThread]);
    }];
    NSBlockOperation *operation3 = [NSBlockOperationblockOperationWithBlock:^{
        NSLog(@"下载图片3---%@", [NSThread currentThread]);
    }];
    NSBlockOperation *operation4 = [NSBlockOperationblockOperationWithBlock:^{
        NSLog(@"下载图片4---%@", [NSThread currentThread]);
    }];
    NSInvocationOperation *operation5 = [[NSInvocationOperationalloc]initWithTarget:selfselector:@selector(download)object:nil];
   
    [queue addOperation:operation1];
    [queue addOperation:operation2];
    [queue addOperation:operation3];
    [queue addOperation:operation4];
    [queue addOperation:operation5];
    [queue addOperationWithBlock:^{
        NSLog(@"下载图片5---%@", [NSThread currentThread]);
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"下载图片6---%@", [NSThread currentThread]);
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"下载图片7---%@", [NSThread currentThread]);
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"下载图片8---%@", [NSThread currentThread]);
    }];
    [queue addOperationWithBlock:^{
        NSLog(@"下载图片9---%@", [NSThread currentThread]);
    }];
   
    [queue cancelAllOperations];