IOS开发学习笔记034-UIScrollView-自动滚动

1     [self performSelector:@selector(hideHUD) withObject:nil afterDelay:2.0];
2     - (void)hideHUD
3     {
4         _hudLable.hidden = YES;
5     }

1     dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.5 * NSEC_PER_SEC)),
2                 dispatch_get_main_queue(), ^{
3         _hudLable.hidden = YES;
4     });

1     [NSTimer scheduledTimerWithTimeInterval:3.0
2         target:self selector:@selector(hideHUD) userInfo:nil repeats:NO];

 1     // 1 创建定时器，由系统控制其生命周期
 2     [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
 3     // 2 创建定时器，不过是局部变量
 4     //NSTimer *timer = [NSTimer timerWithTimeInterval:2.0 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
 5     // 手动启动定时器
 6     //[timer fire];
 7 
 8     - (void)nextPage
 9     {
10         NSLog(@"nextPage:%ld", self.pageControl.currentPage);
11 
12     }

1 - (void)startTimer
2 {
3     //  创建定时器
4     self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
5     // 设置计时器线程的优先级和其他线程一样
6     [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
7 }

1 @property (strong, nonatomic ) NSTimer *timer; //计时器

1 // xib 初始化完毕会调用这个方法
2 - (void)awakeFromNib
3 {
4    // NSLog(@"awakeFromNib-----");
5     
6     // 开启定时器
7     [self startTimer];
8 } 

1 - (void)startTimer
2 {
3     //  创建定时器
4     self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
5     // 设置计时器线程的优先级和其他线程一样
6     [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
7 }

 1 - (void)nextPage
 2 {
 3     NSLog(@"nextPage---");
 4     // 下一个页面，对总数取余的页码，循环滚动
 5     NSInteger page = (self.pageControl.currentPage + 1) % self.scrollView.subviews.count;
 6     // 计算偏移量，索引值和scrollView宽度的积
 7     CGPoint offset = CGPointMake(page * self.scrollView.frame.size.width, 0);
 8     // 设置新的偏移量
 9     [self.scrollView setContentOffset:offset animated:YES];
10 }

 1 #pragma mark - 定时器
 2 - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
 3 {
 4     // 没有拖动图片就开始定时器
 5     [self startTimer];
 6 }
 7 
 8 - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
 9 {
10     // 一旦开始拖动就停止计时器
11     [self stopTimer];
12 }

 1 - (void)startTimer
 2 {
 3     //  创建定时器
 4     self.timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage) userInfo:nil repeats:YES];
 5     // 设置计时器线程的优先级和其他线程一样
 6     [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];
 7 }
 8 
 9 
10 - (void)stopTimer
11 {
12     [self.timer invalidate]; // 停止计时器
13     self.timer = nil; //清空指针
14 }