最后的效果:
结构分析:该界面主要是有两个UIScrollView组成,上面的UIScrollView用于存放一组带有点击手势的UILabel(也可以是按钮),下面的UIScrollView用于显示对面标题的UIViewController。
当点击上面的UILabel(或UIButton)时,下面的UIScrollView就移动到对应的位置显示标题对应的UIController的内容。
/**
点击上面的标题label
*/
- (void)respondsToTitleLabel:(UITapGestureRecognizer *)tapGR {
// 选中label
[self selectedLabel:(UILabel *)tapGR.view];
// 显示对应控制器的view
[self showContentVC:tapGR.view.tag - 200];
}
当滑动下面的UIScrollView显示对应标题的内容时,上面的UIScrollView也移动到对应的位置,将该内容对应的UILabel(或UIButton)设为选中状态。
#pragma mark - UIScrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// 获取当前页数
CGFloat currentPage = scrollView.contentOffset.x / SCREENWIDTH;
// 获取当前选中label
UILabel *currentSelectedLabel = [self.titleScrollView viewWithTag:200 + currentPage];
// 获取上一个选中label
UILabel *lastSelectedLabel;
if (currentPage + 1 < self.contentVCClassArray.count - 1) {
lastSelectedLabel = [self.titleScrollView viewWithTag:201 + currentPage];
}
// 计算上一个选中label缩放比例
CGFloat lastSelectedLabelScale = currentPage - (NSInteger)currentPage;
// 计算当前选中label缩放比例
CGFloat currentSelectedLabelScale = 1 - lastSelectedLabelScale;
// 缩放
currentSelectedLabel.transform = CGAffineTransformMakeScale(currentSelectedLabelScale * 0.3 + 1, currentSelectedLabelScale * 0.3 + 1);
lastSelectedLabel.transform = CGAffineTransformMakeScale(lastSelectedLabelScale * 0.3 + 1, lastSelectedLabelScale * 0.3 + 1);
// 颜色渐变
currentSelectedLabel.textColor = [UIColor colorWithRed:currentSelectedLabelScale green:0 blue:0 alpha:1];
lastSelectedLabel.textColor = [UIColor colorWithRed:lastSelectedLabelScale green:0 blue:0 alpha:1];
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
// 选中label
[self selectedLabel:(UILabel *)[self.titleScrollView viewWithTag:200 + scrollView.contentOffset.x / SCREENWIDTH]];
}
属性介绍:
@property (nonatomic, weak) UILabel *currentSelectedTitleLabel; // 当前选中标题Label
@property (nonatomic, strong) UIScrollView *titleScrollView;
@property (nonatomic, strong) UIScrollView *contentScrollView;
@property (nonatomic, copy) NSArray *titleArray; // 标题数组
@property (nonatomic, copy) NSArray *contentVCClassArray; // 内容控制器类名数组
懒加载:
#pragma mark - Getters And Setters
- (UIScrollView *)titleScrollView {
if (!_titleScrollView) {
_titleScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 64, SCREENWIDTH, 44)];
_titleScrollView.contentSize = CGSizeMake(titleLabelWidth * self.contentVCClassArray.count, 0);
// 隐藏水平滚动条
_titleScrollView.showsHorizontalScrollIndicator = NO;
}
return _titleScrollView;
}
- (UIScrollView *)contentScrollView {
if (!_contentScrollView) {
_contentScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, CGRectGetMaxY(self.titleScrollView.frame), SCREENWIDTH, SCREENHEIGHT - 44)];
_contentScrollView.contentSize = CGSizeMake(SCREENWIDTH * self.contentVCClassArray.count, 0);
// 开启分页
_contentScrollView.pagingEnabled = YES;
// 关闭回弹
_contentScrollView.bounces = NO;
// 隐藏水平滚动条
_contentScrollView.showsHorizontalScrollIndicator = NO;
// 设置代理
_contentScrollView.delegate = self;
}
return _contentScrollView;
}
- (NSArray *)titleArray {
if (!_titleArray) {
_titleArray = @[@"红", @"蓝", @"绿", @"黄", @"紫", @"橘"];
}
return _titleArray;
}
- (NSArray *)contentVCClassArray {
if (!_contentVCClassArray) {
_contentVCClassArray = @[@"DBHRedViewController",
@"DBHBlueViewController",
@"DBHGreenViewController",
@"DBHYellowViewController",
@"DBHPurPleViewController",
@"DBHOrangeViewController"];
}
return _contentVCClassArray;
}
方法介绍:
#pragma mark - Private Methods
/**
添加所有子控制器对应的标题
*/
- (void)addTitleLabels {
for (NSInteger i = 0; i < self.contentVCClassArray.count; i++) {
UILabel *titleLabel = [[UILabel alloc] init];
titleLabel.tag = 200 + i;
titleLabel.frame = CGRectMake(titleLabelWidth * i, 0, titleLabelWidth, 44);
titleLabel.text = self.titleArray[i];
titleLabel.textAlignment = NSTextAlignmentCenter;
titleLabel.highlightedTextColor = [UIColor redColor];
titleLabel.userInteractionEnabled = YES;
UITapGestureRecognizer *tapGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(respondsToTitleLabel:)];
[titleLabel addGestureRecognizer:tapGR];
// 默认选中第1个titleLabel
if (!i) {
[self respondsToTitleLabel:tapGR];
}
[self.titleScrollView addSubview:titleLabel];
}
}
/**
添加所有子控制器
*/
- (void)addChildViewControllers {
for (NSInteger i = 0; i < self.contentVCClassArray.count; i++) {
NSString *contentVCClassName = self.contentVCClassArray[i];
UIViewController *contentVC = [[NSClassFromString(contentVCClassName) alloc] init];
[self addChildViewController:contentVC];
contentVC.view.frame = CGRectMake(SCREENWIDTH * i, 0, SCREENWIDTH, SCREENHEIGHT);
[self.contentScrollView addSubview:contentVC.view];
}
}
/**
选中label
*/
- (void)selectedLabel:(UILabel *)label {
// 还原前一个选中label的属性
self.currentSelectedTitleLabel.highlighted = NO;
self.currentSelectedTitleLabel.transform = CGAffineTransformIdentity;
self.currentSelectedTitleLabel.textColor = [UIColor blackColor];
// 修改选中label的属性
label.highlighted = YES;
label.transform = CGAffineTransformMakeScale(scale, scale);
// 更改选中的label
self.currentSelectedTitleLabel = label;
// 居中选中的label
CGFloat offsetX = label.center.x - SCREENWIDTH * 0.5;
CGFloat maxOffsetX = self.titleScrollView.contentSize.width - SCREENWIDTH;
if (offsetX < 0) {
offsetX = 0;
} else if (offsetX > maxOffsetX) {
offsetX = maxOffsetX;
}
[self.titleScrollView setContentOffset:CGPointMake(offsetX, 0) animated:YES];
}
/**
显示选中标题对面的控制器view
@param index 选中标题的下标
*/
- (void)showContentVC:(NSInteger)index {
// 移动内容scrollView到指定位置
self.contentScrollView.contentOffset = CGPointMake(SCREENWIDTH * index, 0);
}
代码到这里就完毕了,具体使用可以参考源码demo,这里所有的子控制器一开始就成为了当前主控制器的子控制器。因为我这里的标签数量比较少,所以所有子控制器的视图当成为子控制器的时候就已经添加到内容UIScrollView上面了,当标签数量比较多时,可以在一开始的时候只添加为子控制器,无须将子控制器的视图加载到内容UIScrollview上,当需要显示的时候再加上去以节省内存,不过这样的话,当第一次加载视图的时候会有一个明显的空白区域,看着不大舒服。
Demo地址