#import "ViewController.h" #define kURLString1 @"http://www.nbsheji.cn/uploadfiles/2010113143922418.jpg" #define kURLString2 @"http://amuse.nen.com.cn/imagelist/11/21/9as70n3ir61b.jpg" @interface ViewController () @property (retain, nonatomic) IBOutlet UIImageView *FirstView;//第1個圖片 @property (retain, nonatomic) IBOutlet UIImageView *secondView;//第2個圖片 @property(nonatomic,retain)NSMutableArray *dataSource;//存儲要求下來的數據 @end @implementation ViewController //懶加載 - (NSMutableArray *)dataSource{ if (_dataSource == nil) { self.dataSource = [NSMutableArray arrayWithCapacity:0]; } return [[_dataSource retain]autorelease]; }

- (IBAction)handleSerialQueue:(UIButton *)sender { //獲得系統串行隊列 // (1)向系統的創建的串行隊列中添加異步任務,還是在主線程中完成; // (2)向系統創建的串行隊列中添加同步任務,會造成線程死鎖,致使其他人沒法履行; dispatch_queue_t queue1 = dispatch_get_main_queue(); //01:隊列的唯1標識,采取反域名情勢 //02:隊列的屬性類型,也就是標識這個隊列是串行隊列還是并行隊列 // (1)自己創建的串行隊列中添加異步任務是在子線程中完成任務; // (2)自己創建的串行隊列中添加同步任務是在主線程中完成任務; dispatch_queue_t queue2 = dispatch_queue_create("com.xcqnzf.xuchang", DISPATCH_QUEUE_SERIAL); /* //異步任務 //第1個參數:任務添加到隊列名稱 //第2個參數:block履行任務內容 dispatch_async(queue2, ^{ NSLog(@"任務1 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_async(queue2, ^{ NSLog(@"任務2 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_async(queue2, ^{ NSLog(@"任務3 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); //釋放掉自己的創建的隊列,出現create就要釋放 dispatch_release(queue2); */ //同步任務 dispatch_sync(queue2, ^{ NSLog(@"任務1 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_sync(queue2, ^{ NSLog(@"任務2 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_sync(queue2, ^{ NSLog(@"任務3 %@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); // 總結:同步任務:不管在哪個隊列中都是主線程中履行,但是不能將其添加到系統自帶的串行隊列中; // 異步任務:在自己創建的串行隊列中,在子線程中履行,如果是系統創建的隊列在主線程中履行; }

- (IBAction)handleConcurrentQueue:(UIButton *)sender { //1.獲得系統自帶的并行隊列 //01.隊列的優先級 //02.預留參數 給0 dispatch_queue_t queue1 = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); //2.自己創建并行隊列 (1般不自己創建并行隊列,系統的并行隊列已夠用了) dispatch_queue_t queue2 = dispatch_queue_create("com.xcqnzf.xuchang", DISPATCH_QUEUE_CONCURRENT); //同步任務 dispatch_sync(queue1, ^{ NSLog(@"同步任務%@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); //異步任務 dispatch_async(queue2, ^{ NSLog(@"任務1%@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_async(queue2, ^{ NSLog(@"任務2%@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); }); dispatch_async(queue2, ^{ NSLog(@"任務3%@ %d",[NSThread currentThread],[NSThread currentThread].isMainThread); //線程間的通訊 //由子線程回到主線程 //獲得系統的串行隊列 dispatch_async(dispatch_get_main_queue(), ^{ NSLog(@"我回到主線程了"); }); }); //釋放出現create就要釋放 dispatch_release(queue2); }

- (IBAction)handleGroupQueue:(UIButton *)sender { //1.創建并行隊列,并履行任務 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); __block typeof(self)weakSelf = self; //創建分組異步同步任務 dispatch_group_t group = dispatch_group_create(); //01.分組名 //02.要添加的隊列名 //03.要履行的任務 dispatch_group_async(group, queue, ^{ NSURL *urlString = [NSURL URLWithString:kURLString1]; NSData *data1 = [NSData dataWithContentsOfURL:urlString]; //使用數組寄存要求下來的數據 [weakSelf.dataSource addObject:data1]; }); dispatch_group_async(group, queue, ^{ NSURL *url = [NSURL URLWithString:kURLString2]; NSData *data2 = [NSData dataWithContentsOfURL:url]; [weakSelf.dataSource addObject:data2]; }); //分組中的任務都完成后會自動觸發下面的方法 dispatch_group_notify(group, queue, ^{ weakSelf.FirstView.image = [UIImage imageWithData:weakSelf.dataSource[0]]; weakSelf.secondView.image = [UIImage imageWithData:weakSelf.dataSource[1]]; }); //釋放分組 dispatch_release(group); }

- (IBAction)handleBarrierQueue:(UIButton *)sender { //1.使用障礙隊列只能使用自己創建的并列隊列,不能使用系統的并行隊列 dispatch_queue_t queue = dispatch_queue_create("com.xcqnzf.xuchang", DISPATCH_QUEUE_CONCURRENT); //2.往并行隊列中添加任務 dispatch_async(queue, ^{ NSLog(@"A寫入文件"); }); dispatch_async(queue, ^{ NSLog(@"B寫入文件"); }); dispatch_async(queue, ^{ NSLog(@"C寫入文件"); }); //添加障礙,間隔寫入和讀取的任務,障礙任務之前的任務都完成了才能繼續完成障礙任務后面的任務 dispatch_barrier_async(queue, ^{ NSLog(@"我是障礙任務,讀取的任務先等會"); }); dispatch_async(queue, ^{ NSLog(@"D讀取文件"); }); dispatch_async(queue, ^{ NSLog(@"D讀取文件"); }); dispatch_async(queue, ^{ NSLog(@"E讀取文件"); }); //3.釋放 dispatch_release(queue); }

- (IBAction)handleOnce:(UIButton *)sender { static dispatch_once_t oneToken ; // dispatch_once(&oneToken, ^{ NSLog(@"有本事讓我走兩次"); }); }

Helper.h @interface Helper : NSObject + (Helper *)shareHelper; @end Helper.h @implementation Helper static Helper *helper = nil; + (Helper *)shareHelper{ //VIP static dispatch_once_t oneToken; dispatch_once(&oneToken, ^{ helper = [[Helper alloc]init]; }); return helper; } @end

- (IBAction)handleRepeat:(UIButton *)sender { //1.獲得系統的并行隊列 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); //2.向隊列中添加重復任務 //01.任務重復的次數 //02.任務添加到的隊列名稱 //03.當前是第幾次重復這個任務 dispatch_apply(10, queue, ^(size_t times) { NSLog(@"我要吃爆米花,這是我第%ld吃",times); }); }

- (IBAction)handlePing:(UIButton *)sender { //創建1個延遲任務 //01. DISPATCH_TIME_NOW 表示從當前時間開始 //02. 表示過量少秒才去履行任務 //03. 串行的主隊列 dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ NSLog(@"延遲任務在主線程中履行"); }); }

//釋放
- (void)dealloc {
    [_FirstView release];
    [_secondView release];
    self.dataSource = nil;
    [super dealloc];
}