1、第一种方式
- (void)group1 {
dispatch_group_t group = dispatch_group_create();
dispatch_queue_t q = dispatch_get_global_queue(0, 0);
dispatch_group_enter(group);
dispatch_async(q, ^{
NSLog(@"print A: ");
dispatch_group_leave(group);
});
dispatch_group_enter(group);
dispatch_async(q, ^{
NSLog(@"print B:");
[NSThread sleepForTimeInterval:1.0];
dispatch_group_leave(group);
});
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
NSLog(@"print C:");
});
}
2、第二种方式
- (void)group2 {
dispatch_group_t group = dispatch_group_create();
dispatch_queue_t q = dispatch_get_global_queue(0, 0);
dispatch_group_async(group, q, ^{
NSLog(@"print A: ");
});
dispatch_group_async(group, q, ^{
NSLog(@"print B:");
[NSThread sleepForTimeInterval:1.0];
});
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
NSLog(@"print C: ");
});
}
