GCD

来源：互联网发布：二分排序算法c 编辑：程序博客网时间：2024/04/27 14:08

异步下载

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{//扔给另外的cpu处理

        NSLog(@"downData");
        dispatch_async(dispatch_get_main_queue(), ^{
            NSLog(@"refresUI");
        });

});

队列下载提交给系统并发但是仍然可以有优先级，但是也没多大用途.

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_group_t group = dispatch_group_create();
    dispatch_group_async(group, queue, ^{

        for (int i =0; i<1; i++)
        {
             NSLog(@"dosomething");
        }

    });

    dispatch_group_notify(group, dispatch_get_main_queue(), ^{
        NSLog(@"updateUi");
    });

dispatch_release(group);

//dispatch_group 可以向 dispathc_queue 提交代码块。dispatch_group 可以转移执行 dispathc_queue

///有点象队列了

dispatch_queue_t testQueue =dispatch_queue_create("com.hu.qinghe",DISPATCH_QUEUE_SERIAL);

dispatch_async(testQueue, ^{

for (int i =0; i<100; i++) {

NSLog(@"i------;%d",i);

}

});

dispatch_async(testQueue, ^{

for (int i =0; i<100; i++) {

NSLog(@"j=====;%d",i);

}

});

NSLog(@"backGround");

dispatch_release(testQueue);