Question

在我的应用程序中使用UIControlpage。加载图像并在页面控制中成功显示。但我想显示图像动画，如从右到左移动。使用定时器调用页面控制并增加数组计数。

////使用NSTimer调用函数来显示动画。

[NSTimer scheduledTimerWithTimeInterval:5.0
                                     target:self
                                   selector:@selector(loadNextController)
                                   userInfo:nil
                                    repeats:YES];

ScrollViewPage = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 20, frameX, frameY)];
ScrollViewPage.pagingEnabled = YES;
ScrollViewPage.backgroundColor=[UIColor redColor];
ScrollViewPage.delegate = self;
ScrollViewPage.backgroundColor = [UIColor clearColor];
ScrollViewPage.contentSize = CGSizeMake(frameX, frameY);
ScrollViewPage.showsHorizontalScrollIndicator = NO;


ScrollViewPage.pagingEnabled = YES;
pageControl = [[UIPageControl alloc] init];
pageControl.frame = CGRectMake(100,self.view.frame.size.height-100,self.view.frame.size.width-200,100);
pageControl.numberOfPages = [_pageImages count];
pageControl.currentPage = 0;

[self.view addSubview: ScrollViewPage];

for(int i = 0; i < [_pageImages count]; i++)
    {

        NSURL *url = [NSURL URLWithString:[_pageImages objectAtIndex:i]];
        NSData *data = [[NSData alloc] initWithContentsOfURL:url];
        UIImage *tmpImage = [UIImage imageWithData:data];
        _backgroundImageView = [[UIImageView alloc] initWithImage:tmpImage];
         _backgroundImageView.frame = CGRectMake(frameX * i, 0.0, frameX, frameY);
        [ScrollViewPage addSubview:_backgroundImageView];


    }

ScrollViewPage.contentSize = CGSizeMake(frameX*[_pageImages count], frameY);
pageControl.backgroundColor=[UIColor orangeColor];
[self.view addSubview:pageControl];
[pageControl addTarget:self action:@selector(pageTurn:) forControlEvents:UIControlEventValueChanged];

/////这里调用定时器功能

- (void)loadNextController
{
     pageControl.currentPage = (pageControl.currentPage+1)%self.pageImages.count;
     ScrollViewPage.contentOffset = CGPointMake(pageControl.currentPage * self.view.bounds.size.width, 0);
}

这里我需要在uipagecontrol中显示从左到右的移动。帮帮我......

Answer 1

一般来说，你应该总是写出你当前的结果是什么，预期的结果是什么以及你尝试了什么。

我只能猜测你遇到的问题是没有动画。滚动视图有一个方法setContentOffset:animated，您可以使用该方法为过渡设置动画。另一种方法是使用UIView animateWithDuration并在方法块中设置偏移量。

尝试其中任何一个或两个......

[ScrollViewPage setContentOffset:CGPointMake(pageControl.currentPage * self.view.bounds.size.width, 0) animated:YES];

或者

[UIView animateWithDuration:0.2 animations:^{
        ScrollViewPage.contentOffset = CGPointMake(pageControl.currentPage * self.view.bounds.size.width, 0);
}];

编辑：循环图片。

要循环图像，您当时只需要滚动视图上的2个图像。我将向您展示3的概念，您可以尝试使用它。

NSArray *allImages;
NSInteger currentIndex = 0;
UIScrollView *scrollView;
UIImageView *imageViews[3];

- (void)begin {

    scrollView.contentSize = CGSizeMake(scrollView.frame.size.width*3.0, scrollView.frame.size.height); // always have 3 images at the time
    scrollView.contentOffset = CGPointMake(scrollView.frame.size.width, 0.0); // put to center

    for(int i=0; i<3; i++) {
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(scrollView.frame.size.width*i, 0.0, scrollView.frame.size.width, scrollView.frame.size.height)];
        [scrollView addSubview:imageView];
        imageView[i] = imageView;
    }
    [self layoutForIndex:currentIndex];
}
- (void)nextImage {
    currentIndex++;
    [self layoutForIndex:currentIndex];

    scrollView.contentOffset = CGPointZero;
    [scrollView setContentOffset:CGPointMake(scrollView.frame.size.width, 0.0) animated:YES]
}

- (void)layoutForIndex:(NSInteger)index {
    if(allImages.count > 0) { // we need at least one image to do something
        for(int i=0; i<3; i++) {
            // do the circling
            NSInteger imageIndex = index-1+i;
            while(imageIndex < 0) imageIndex+=allImages.count;
            while(imageIndex >= allImages.count) imageIndex-=allImages.count;

            imageViews[i].image = imageViews[imageIndex];
        }
    }
}

但总的来说，你正在做的事情甚至不需要滚动视图。接下来，您只需在当前图像旁边添加另一个图像视图，然后使用UIView动画重新定位两个图像视图。

UIpagecontrol需要动画左移

1 个答案: