advertScroll.gif
调用示例代码如下：
_labelView = [[LFAdvertScrollView alloc] initWithFrame:CGRectMake(0, 100, ScreenWidth, 40)];
_labelView.totalCount = 4;
_labelView.dataSource = self;
_labelView.delegate = self;
[self.view addSubview:_labelView];
_attbriuteView = [[LFAdvertScrollView alloc] initWithFrame:CGRectMake(0, 160, ScreenWidth, 60)];
_attbriuteView.totalCount = 4;
_attbriuteView.dataSource = self;
_attbriuteView.delegate = self;
[self.view addSubview:_attbriuteView];
_imageView = [[LFAdvertScrollView alloc] initWithFrame:CGRectMake(0, 240, ScreenWidth, 200)];
_imageView.totalCount = 4;
_imageView.dataSource = self;
_imageView.delegate = self;
[self.view addSubview:_imageView];
遵循代理要实现的方法：
- (Class)customViewClassForAdvertScrollView:(LFAdvertScrollView *)view {
if (view == _labelView) {
return [UILabel class];
} else if (view == _imageView) {
return [UIImageView class];
} else {
return [CustomAdvertView class];
}
}
- (void)configCustomView:(UIView *)view forIndex:(NSInteger)index advertView:(nonnull LFAdvertScrollView *)advertView {
if (advertView == _labelView) {
UILabel *testLabel = (UILabel *)view;
testLabel.text = @[@"I'm Li Bai",@"I'm Du Fu",@"I'm Bai Ju Yi",@"I'm Wang An Shi"][index];
testLabel.textAlignment = NSTextAlignmentCenter;
testLabel.textColor = [UIColor purpleColor];
testLabel.font = [UIFont boldSystemFontOfSize:16];
testLabel.backgroundColor = [UIColor cyanColor];
} else if (advertView == _imageView) {
UIImageView *imageView = (UIImageView *)view;
imageView.image = [UIImage imageNamed:@[@"h1.jpg",
@"h2.jpg",
@"h3.jpg",
@"h4.jpg"][index]];
} else {
CustomAdvertView *customView = (CustomAdvertView *)view;
customView.leftImage.image = [UIImage imageNamed:@[@"h1.jpg",
@"h2.jpg",
@"h3.jpg",
@"h4.jpg"][index]];
customView.rightLabel.text = @[@"I'm Li Bai,I'm Li Bai,I'm Li Bai,I'm Li Bai,I'm Li Bai",@"I'm Du Fu",@"I'm Bai Ju Yi",@"I'm Wang An Shi"][index];
}
}
重点来了，看了很多都是基于UICollectionView实现的，自动滚动模式下，会返回很多个Item，我这里尝试用UIScrollview复用三个view来实现自动滚动，核心思路是用户看到的永远是中间的那个view，通过控制偏移量来实现自动滚动效果。
LFAdvertScrollView.h文件内容：
@class LFAdvertScrollView;
@protocol LFAdvertScrollViewDataSource
/**
返回要滚动的视图类型
@param view LFAdvertScrollView
@return 返回要滚动的视图类型,!!!:必须是继承于UIView实现的类
*/
- (Class)customViewClassForAdvertScrollView:(LFAdvertScrollView *)view;
@end
@protocol LFAdvertScrollViewDelegate
/**
给自定义视图赋值
@param view 赋值的视图
@param index 第几个视图
@param advertView LFAdvertScrollView
*/
- (void)configCustomView:(UIView *)view forIndex:(NSInteger)index advertView:(LFAdvertScrollView *)advertView;
/**
点击回调
@param advertView LFAdvertScrollView
@param index 第几个视图
*/
- (void)advertView:(LFAdvertScrollView *)advertView didSelectViewIndex:(NSInteger )index;
@end
@interface LFAdvertScrollView : UIView
/**
数据源个数，必传项
*/
@property (nonatomic, assign) NSInteger totalCount;
/**
滚动时间间隔
*/
@property (nonatomic, assign) NSTimeInterval autoScrollInterval;
@property (nonatomic, weak) iddelegate;
@property (nonatomic, weak) iddataSource;
@end
实现方式很简单，就是复用三个view实现无限轮播，点击事件只添加到中间的view上面，然后点击回调出当前页码
这是主要实现部分：
///设置事件代理
- (void)setDelegate:(id)delegate {
_delegate = delegate;
if ([_delegate respondsToSelector:@selector(configCustomView:forIndex:advertView:)]) {
[self.delegate configCustomView:self.topView forIndex:self.totalCount - 1 advertView:self];
[self.delegate configCustomView:self.middleView forIndex:0 advertView:self];
[self.delegate configCustomView:self.bottomView forIndex:1 advertView:self];
}
}
///设置视图类型代理
- (void)setDataSource:(id)dataSource {
_dataSource = dataSource;
if (self.dataSource && [self.dataSource respondsToSelector:@selector(customViewClassForAdvertScrollView:)]) {
///拿到用户自定义的视图类名
Class CustomClass = [self.dataSource customViewClassForAdvertScrollView:self];
self.topView = [[CustomClass alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
self.middleView = [[CustomClass alloc] initWithFrame:CGRectMake(0, self.frame.size.height * 1, self.frame.size.width, self.frame.size.height)];
///用户看到的只有中间视图，所以为了简单起见，只需要添加中间视图的点击响应
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(customViewTap)];
[self.middleView addGestureRecognizer:tap];
self.bottomView = [[CustomClass alloc] initWithFrame:CGRectMake(0, self.frame.size.height * 2, self.frame.size.width, self.frame.size.height)];
[self.contentView addSubview:self.topView];
[self.contentView addSubview:self.middleView];
[self.contentView addSubview:self.bottomView];
}
}
#pragma mark - timer执行的方法
- (void)automaticScroll
{
self.currentPage++;
if (self.currentPage == self.totalCount) {
self.currentPage = 0;
}
[UIView animateWithDuration:1 animations:^{
///动画发生的滑动
self.middleView.userInteractionEnabled =NO;
self.contentView.contentOffset =CGPointMake(0, CGRectGetHeight(self.contentView.frame) * 2);
} completion:^(BOOL finished) {
///滑动完成后，把当前现实的imageview重现移动回中间位置，此处不能使用动画，用户感觉不到
///移动前,先把中间imageview的image设置成当前现实的iamge
self.middleView.userInteractionEnabled = YES;
if (self.delegate && [self.delegate respondsToSelector:@selector(configCustomView:forIndex:advertView:)]) {
[self.delegate configCustomView:self.topView forIndex:self.currentPage == 0 ?self.totalCount - 1 : self.currentPage - 1 advertView:self];
[self.delegate configCustomView:self.middleView forIndex:self.currentPage advertView:self];
[self.delegate configCustomView:self.bottomView forIndex:self.currentPage == self.totalCount - 1 ? 0 : self.currentPage + 1 advertView:self];
}
self.contentView.contentOffset =CGPointMake(0, CGRectGetHeight(self.contentView.frame) * 1);
}];
}
#pragma mark - 用户点击
-(void)customViewTap{
if (self.delegate && [self.delegate respondsToSelector:@selector(advertView:didSelectViewIndex:)]) {
[self.delegate advertView:self didSelectViewIndex:self.currentPage];
}
}
代码基本就这些了， 写这篇纯属算是个人笔记，不喜勿喷，有更好的想法或者意见的欢迎大家指出。