iOS dispatch_source_timer 分享demo

DISPATCH_SOURCE_TYPE_TIMER

另外一种gcd封装好的计时器处理工具，上一小段使用demo代码

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
{
    UIProgressView*_progressView;
    dispatch_source_t _timerSource;
    CGFloat progressTotal;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    progressTotal = 0;

    [self setupUI];
}

- (void)setupUI
{
    _progressView = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleDefault];
    _progressView.progressTintColor = [UIColor blueColor];
    _progressView.trackTintColor = [UIColor redColor];
    [_progressView setProgress:0];
    _progressView.frame = CGRectMake(10, 100, self.view.frame.size.width - 20, 5);
    _progressView.transform = CGAffineTransformMakeScale(1.0f,3.0f);
    [self.view addSubview:_progressView];
    
    UIButton*button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setBackgroundColor:[UIColor blackColor]];
    [button setTitle:@"start" forState:UIControlStateNormal];
    [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [self.view addSubview:button];
    button.frame = CGRectMake(180, 160, 50, 30);
    [button addTarget:self action:@selector(gcdResourceTest) forControlEvents:UIControlEventTouchUpInside];
}

- (void)gcdResourceTest
{
    dispatch_queue_t timerQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0);
    _timerSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, timerQueue);
    double interval = 1 * NSEC_PER_SEC;
    dispatch_source_set_timer(_timerSource, dispatch_time(DISPATCH_TIME_NOW, 0), interval, 0);

    dispatch_block_t executingBlock = ^{
        NSLog(@"progress:%.2f",progressTotal);
        progressTotal += 0.1;
        dispatch_async(dispatch_get_main_queue(), ^{
            [_progressView setProgress:progressTotal animated:YES];
        });
        if(progressTotal>=1.0)
        {
            dispatch_source_cancel(_timerSource);
        }
    };
    dispatch_source_set_event_handler(_timerSource, [executingBlock copy]);
    dispatch_source_set_cancel_handler(_timerSource, ^{
        NSLog(@"process canceled");
    });
    dispatch_resume(_timerSource);
}


@end

　　输出：

2016-03-29 18:27:41.858 DispatchSourceTestOne[36439:255867] progress:0.00
2016-03-29 18:27:42.858 DispatchSourceTestOne[36439:255867] progress:0.10
2016-03-29 18:27:43.859 DispatchSourceTestOne[36439:255867] progress:0.20
2016-03-29 18:27:44.860 DispatchSourceTestOne[36439:255867] progress:0.30
2016-03-29 18:27:45.859 DispatchSourceTestOne[36439:255867] progress:0.40
2016-03-29 18:27:46.858 DispatchSourceTestOne[36439:255867] progress:0.50
2016-03-29 18:27:47.858 DispatchSourceTestOne[36439:255867] progress:0.60
2016-03-29 18:27:48.861 DispatchSourceTestOne[36439:255867] progress:0.70
2016-03-29 18:27:49.862 DispatchSourceTestOne[36439:255867] progress:0.80
2016-03-29 18:27:50.860 DispatchSourceTestOne[36439:255867] progress:0.90
2016-03-29 18:27:51.857 DispatchSourceTestOne[36439:255867] progress:1.00
2016-03-29 18:27:51.858 DispatchSourceTestOne[36439:255867] process canceled

 

1秒调用一次，当进度大于等于1timer停止，cancel block回调

这里注意dispatch_source_t  timerSource是一个实例变量，如果放在函数里面创建，局部变量内存释放比较早，会没有效果。