設(shè)置一個(gè)場(chǎng)景,有10個(gè)異步線程,當(dāng)10個(gè)異步線程全部完成后,再執(zhí)行某一項(xiàng)的操作.

使用dispatch_queue的并行隊(duì)列. 相機(jī)而言的就有dispatch_group

? ? dispatch_queue_tdispatchQueue =dispatch_queue_create("ted.queue.next",DISPATCH_QUEUE_CONCURRENT);

dispatch_group_tdispatchGroup =dispatch_group_create();

dispatch_group_async(dispatchGroup, dispatchQueue, ^(){

NSLog(@"dispatch_1");

});

dispatch_group_async(dispatchGroup, dispatchQueue, ^(){

NSLog(@"dspatch_2");

});

dispatch_group_notify(dispatchGroup,dispatch_get_main_queue(), ^(){

NSLog(@"全部執(zhí)行完畢.");

});

NSLog(@"這個(gè)線程什么時(shí)候走?");

2015-11-03 10:51:31.753 xcodedemo[4895:2175050]這個(gè)線程什么時(shí)候走?

2015-11-03 10:51:31.754 xcodedemo[4895:2175095] dspatch_2

2015-11-03 10:51:31.754 xcodedemo[4895:2175094] dispatch_1

2015-11-03 10:51:31.821 xcodedemo[4895:2175050]全部執(zhí)行完畢.

這是打印的log. 線程.dispatch_1和dspatch_2 是無(wú)序的.. ? ? ? ??一目了然了