1、创建队列组
dispatch_group_t group = dispatch_group_create();
2、创建全局队列
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
3、执行异步任务
dispatch_group_async(group, queue, ^{
NSLog(@"1---%@",[NSThread currentThread]);
});
dispatch_group_async(group, queue, ^{
NSLog(@"2---%@",[NSThread currentThread]);
});
dispatch_group_async(group, queue, ^{
NSLog(@"3---%@",[NSThread currentThread]);
});
dispatch_group_async(group, queue, ^{
NSLog(@"4---%@",[NSThread currentThread]);
});
4、当全部任务执行完毕的时候执行队列组之后的任务
dispatch_group_notify(group, queue, ^{
NSLog(@"所有的任务都执行完毕了");
});
