App 启动的引导页制作,如下步骤
- 设置 ViewController 的 View 为 ImageView;
- 添加 ScrollView 到 ImageView 中;
- 添加 PageControl 到 ImageView 中;
- 设置 ScrollView 的代理方法 scrollViewDidEndDecelerating
#import "LoadingViewController.h"
@interface LoadingViewController ()<UIScrollViewDelegate> {
UIScrollView *_scrollView;
UIPageControl *_pageControl;
int _count;
}
@end
@implementation LoadingViewController
- (void) loadView {
UIImageView *imageView = [[UIImageView alloc] init];
imageView.frame = [UIScreen mainScreen].bounds;
imageView.image = [UIImage imageNamed:@"loading_background.png"];
//imageview 默认不能交互
imageView.userInteractionEnabled = YES;
self.view = imageView;
}
- (void)viewDidLoad {
[super viewDidLoad];
CGSize viewSize = self.view.frame.size;
_count = 4;
_scrollView = [[UIScrollView alloc] init];
_scrollView.frame = self.view.bounds;
_scrollView.showsHorizontalScrollIndicator = NO;
_scrollView.pagingEnabled = YES;
_scrollView.contentSize = CGSizeMake(_count * self.view.bounds.size.width, 0);
_scrollView.delegate = self;
[self.view addSubview:_scrollView];
for (int i = 0; i<_count; i++) {
[self addImageViewAtIndex:i];
}
_pageControl = [[UIPageControl alloc] init];
_pageControl.center = CGPointMake(viewSize.width * 0.5, viewSize.height * 0.9);
_pageControl.bounds = CGRectMake(0, 0, 100, 0);
_pageControl.numberOfPages = _count;
_pageControl.pageIndicatorTintColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"loading_pagecontrol_point.png"]];
_pageControl.currentPageIndicatorTintColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"loading_pagecontrol_checked_point.png"]];
_pageControl.userInteractionEnabled = NO;
[self.view addSubview:_pageControl];
}
- (void) addImageViewAtIndex:(int) index
{
CGSize viewSize = self.view.frame.size;
UIImageView *imageView = [[UIImageView alloc] init];
imageView.frame = CGRectMake(index * viewSize.width, 0, viewSize.width, viewSize.height);
NSString *name = [NSString stringWithFormat:@"loading_%d.png", index+1];
imageView.image = [UIImage imageNamed:name];
[_scrollView addSubview:imageView];
}
- (void) scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
_pageControl.currentPage = scrollView.contentOffset.x / scrollView.frame.size.width;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end
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