//创建队列
dispatch_queue_t queen = dispatch_get_global_queue(0, 0);
//创建队列组
dispatch_group_t group = dispatch_group_create();
//创建队列组线程
dispatch_group_async(group, queen, ^{
NSLog(@"1-%@",[NSThread currentThread]);
});
dispatch_group_async(group, queen, ^{
NSLog(@"2-%@",[NSThread currentThread]);
});
dispatch_group_async(group, queen, ^{
NSLog(@"3-%@",[NSThread currentThread]);
});
dispatch_group_async(group, queen, ^{
NSLog(@"4-%@",[NSThread currentThread]);
});
dispatch_group_notify(group, queen, ^{
NSLog(@"-------done--------");
});
dispatch_group_notify 这个是队列通知,如果以上四个队列任务都完成了,将会在这里进行回调
