Question

我有一个包含4个图像的视图控制器，我实现了这些图像的分页这是我的代码

- (void)viewDidLoad {
    [super viewDidLoad];

    [imageViewObj setImage:[UIImage imageNamed:@"hand1@2x"]];

    NSTimer *ImgChangeTimer = [NSTimer scheduledTimerWithTimeInterval:2.0
                                                               target:self
                                                             selector:@selector(changeImage)
                                                             userInfo:nil
                                                              repeats:YES];

pageControlBeingUsed = NO;

    NSArray *colors = [NSArray arrayWithObjects:[UIImage imageNamed:@"help3@2x"], [UIImage imageNamed:@"help4@2x"], [UIImage imageNamed:@"help2@2x"],[UIImage imageNamed:@"help1@2x"] ,nil];
    for (int i = 0; i < colors.count; i++) {
        CGRect frame;
        frame.origin.x = self.scrollView.frame.size.width *i;
        frame.origin.y = 0;
        frame.size = self.scrollView.frame.size;

        UIImageView*subview = [[UIView alloc] initWithFrame:frame];
        UIImage *imggg = [colors objectAtIndex:i];
        [subview setBackgroundColor:[UIColor colorWithPatternImage:imggg]]; 
        [self.scrollView addSubview:subview];
        [self.scrollView addSubview:imageViewObj];
        [subview release];
        }
    self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * colors.count, self.scrollView.frame.size.height);

    self.pageControl.currentPage = 0;
    self.pageControl.numberOfPages = colors.count;

我需要的是我想在最后一张图片中放置一个关闭按钮，或者关闭按钮被隐藏为前三张图像，并且当用户分页最后一张图片时将取消隐藏。是否有任何方法可以执行此操作？提前致谢。修改

if (self.pageControl.currentPage == 0) {
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"df" message:@"okkkk" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
        [alert show];
        [alert release];
    }

我把它放在viewdidlod中，我得到了alertview

但是当我把“4”而不是“0”时，我没有得到警报视图

Answer 1

尝试使用以下代码，代码段：

    NSInteger page;
        page = (scrollView.contentOffset.x/scrollView.frame.size.width);
    if (page == 3) {
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"df" message:@"okkkk" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];
        [alert show];
        [alert release];
    }

分页错误scrollview

1 个答案: