使用環(huán)境：一個(gè) APP 頁面需要同時(shí)請求多個(gè)接口都完成后再刷新界面

//創(chuàng)建隊(duì)列組
dispatch_group_t group = dispatch_group_create();
//全局串行隊(duì)列
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

dispatch_group_enter(group);
dispatch_async(queue, ^{
// 第一個(gè)任務(wù)
NSLog(@"執(zhí)行第一個(gè)任務(wù)");
dispatch_group_leave(group);
});

dispatch_group_enter(group);
dispatch_async(queue, ^{
// 第二個(gè)任務(wù)
NSLog(@"執(zhí)行第二個(gè)任務(wù)");
dispatch_group_leave(group);
});

dispatch_group_notify(group, dispatch_get_main_queue(), ^{
NSLog(@"執(zhí)行最后的匯總?cè)蝿?wù)");
});