iOS——系统提供的dispatch方法

// 后台执行:

dispatch_async(dispatch_get_global_queue(0,0), ^{

  // something

});

 

// 主线程执行:

dispatch_async(dispatch_get_main_queue(),^{

  // something

});

 

// 一次性执行:

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

  // code to be excuted once

});

 

// 延迟2秒执行:

double delayInSeconds = 2.0;

dispatch_time_y popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);

dispatch_after(popTime, dispatch_get_main_queue(), ^(void){

  // code to be excuted on the main queue after delay

});

posted @ 2015-04-05 11:29  天使的翅膀——  阅读(202)  评论(0编辑  收藏  举报