dispatch_group_t group =dispatch_group_create();

? ? dispatch_queue_t globalQueue=dispatch_get_global_queue(0,0);

? ? ? ? dispatch_group_enter(group);

? ? //模擬多線(xiàn)程耗時(shí)操作dispatch_group_async(group, globalQueue, ^{

? ? ? ? sleep(3);

? ? ? ? NSLog(@"%@---block1結(jié)束。。。",[NSThread currentThread]);

? ? ? ? dispatch_group_leave(group);

? ? });

? ? NSLog(@"%@---1結(jié)束。。。",[NSThread currentThread]);

? ? dispatch_group_enter(group);

? ? //模擬多線(xiàn)程耗時(shí)操作dispatch_group_async(group, globalQueue, ^{

? ? ? ? sleep(3);

? ? ? ? NSLog(@"%@---block2結(jié)束。。。",[NSThread currentThread]);

? ? ? ? dispatch_group_leave(group);

? ? });

? ? NSLog(@"%@---2結(jié)束。。。",[NSThread currentThread]);

? ? dispatch_group_notify(group, dispatch_get_global_queue(0,0), ^{

? ? ? ? NSLog(@"%@---全部結(jié)束。。。",[NSThread currentThread]);

? ? });