IOS第二天多線程-05NSOperationQueue 暫停，和恢複隊列任務

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#import "HMViewController.h"@interface HMViewController () <UITableViewDelegate>@property (weak, nonatomic) IBOutlet UIImageView *imageView;@end@implementation HMViewController- (void)viewDidLoad{    [super viewDidLoad];        }- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    NSOperationQueue *queue = [[NSOperationQueue alloc] init];    [queue addOperationWithBlock:^{        // 1.非同步下載圖片        NSURL *url = [NSURL URLWithString:@"http://d.hiphotos.baidu.com/image/pic/item/37d3d539b6003af3290eaf5d362ac65c1038b652.jpg"];        NSData *data = [NSData dataWithContentsOfURL:url];        UIImage *image = [UIImage imageWithData:data];                // 2.回到主線程，顯示圖片//        [self performSelectorOnMainThread:<#(SEL)#> withObject:<#(id)#> waitUntilDone:<#(BOOL)#>];//        dispatch_async(dispatch_get_main_queue(), ^{//            //        });        [[NSOperationQueue mainQueue] addOperationWithBlock:^{            self.imageView.image = image;        }];    }];}- (void)dependency{    /**     假設有A、B、C三個操作，要求：     1. 3個操作都非同步執行     2. 操作C依賴於操作B     3. 操作B依賴於操作A     */        // 1.建立一個隊列（非主隊列）    NSOperationQueue *queue = [[NSOperationQueue alloc] init];        // 2.建立3個操作    NSBlockOperation *operationA = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"A1---%@", [NSThread currentThread]);    }];    //    [operationA addExecutionBlock:^{    //        NSLog(@"A2---%@", [NSThread currentThread]);    //    }];    //    //    [operationA setCompletionBlock:^{    //        NSLog(@"AAAAA---%@", [NSThread currentThread]);    //    }];        NSBlockOperation *operationB = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"B---%@", [NSThread currentThread]);    }];    NSBlockOperation *operationC = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"C---%@", [NSThread currentThread]);    }];        // 設定依賴    [operationB addDependency:operationA];    [operationC addDependency:operationB];        // 3.添加操作到隊列中（自動非同步執行任務）    [queue addOperation:operationC];    [queue addOperation:operationA];    [queue addOperation:operationB];}- (void)maxCount{    // 1.建立一個隊列（非主隊列）    NSOperationQueue *queue = [[NSOperationQueue alloc] init];        // 2.設定最大並發(最多同時並發執行3個任務)    queue.maxConcurrentOperationCount = 3;        // 3.添加操作到隊列中（自動非同步執行任務，並發）    NSBlockOperation *operation1 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片1---%@", [NSThread currentThread]);    }];    NSBlockOperation *operation2 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片2---%@", [NSThread currentThread]);    }];    NSBlockOperation *operation3 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片3---%@", [NSThread currentThread]);    }];    NSBlockOperation *operation4 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片4---%@", [NSThread currentThread]);    }];    NSInvocationOperation *operation5 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(download) object:nil];        [queue addOperation:operation1];    [queue addOperation:operation2];    [queue addOperation:operation3];    [queue addOperation:operation4];    [queue addOperation:operation5];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片5---%@", [NSThread currentThread]);    }];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片6---%@", [NSThread currentThread]);    }];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片7---%@", [NSThread currentThread]);    }];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片8---%@", [NSThread currentThread]);    }];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片9---%@", [NSThread currentThread]);    }];        [queue cancelAllOperations];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    //    [queue cancelAllOperations]; // 取消隊列中的所有任務（不可恢複）}- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{//    [queue setSuspended:YES]; // 暫停隊列中的所有任務}- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{//    [queue setSuspended:NO]; // 恢複隊列中的所有任務}- (void)download{    NSLog(@"download---%@", [NSThread currentThread]);}- (void)baseUse{    // 1.建立一個隊列（非主隊列）    NSOperationQueue *queue = [[NSOperationQueue alloc] init];        // 2.添加操作到隊列中（自動非同步執行任務，並發）    NSBlockOperation *operation1 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片1---%@", [NSThread currentThread]);    }];    NSBlockOperation *operation2 = [NSBlockOperation blockOperationWithBlock:^{        NSLog(@"下載圖片2---%@", [NSThread currentThread]);    }];        [queue addOperation:operation1];    [queue addOperation:operation2];    [queue addOperationWithBlock:^{        NSLog(@"下載圖片3---%@", [NSThread currentThread]);    }];        // 3個操作並發執行}@end

 

IOS第二天多線程-05NSOperationQueue 暫停，和恢複隊列任務