利用GCD并行多个线程并且等待所有线程结束之后再执行其它任务dispatch_group_t group = dispatch_group_create();dispatch_group_async(group, dispatch_get_global_queue(0,0), ^{// 并行执行的线程一});dispatch_group_async(group, dispatc

dispatch_queue_t queue =dispatch_queue_create("firstQueue",nil); dispatch_sync(queue, ^(void) {//  任务-});dispatch_sync(queue, ^(void) {//任务二 （任务一不执行完不会执行任务二） });

//–––––––––––––––––––––单例.h––––––––––––––––––––––––#import <Foundation/Foundation.h>@interface CaptchaTimerManager :NSObject@property (nonatomic,assign)__blockint timeout;+ (id)sharedT...

__weak __typeof(self) weakself= self; dispatch_async(dispatch_queue_create(0, 0), ^{ // 子线程执行任务（比如获取较大数据） dispatch_async(dispatch_get_main_queue(), ^{ // 通知主线程刷新 ...

//多个异步请求完成后汇总结结果    dispatch_queue_t queue = dispatch_get_global_queue(0,0);    dispatch_group_t group = dispatch_group_create();    dispatch_group_async(group, queue, ^{/*