主要是对悬浮条的处理，刚开始考虑在view上添加一份同样布局的view，通过隐藏和显示来实现，由于存在两个同样布局的view,处理按钮事件逻辑相对复杂，而用改变悬浮条Superview的方式，实现就比较简单。
iOS-UITableView悬停拉伸处理.gif
-(void)createTableView {
self.tableView = [[UITableView alloc] initWithFrame:[UIScreen mainScreen].bounds style:UITableViewStylePlain];
self.tableView.delegate = self;
self.tableView.dataSource = self;
[self.view addSubview:self.tableView];
self.tableView.showsVerticalScrollIndicator = NO;
//没有把头视图添加到tableHeaderView上，而是设置contentInset来实现
self.tableView.contentInset = UIEdgeInsetsMake(OFFSETHEIGHT, 0, 0, 0);
[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"cell"];
[self.tableView addSubview:[self createHeaderView]];
}
-(UIView *)createHeaderView {
self.headerImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, -OFFSETHEIGHT, SCREENW, OFFSETHEIGHT)];
self.headerImageView.image = [UIImage imageNamed:@"my_card_img_bg"];
// 这行对于实现拉伸放大效果很重要
self.headerImageView.contentMode = UIViewContentModeScaleAspectFill;
self.headerImageView.clipsToBounds = YES;
self.headerImageView.userInteractionEnabled = YES;
[self.headerImageView addSubview:self.btnView];
return self.headerImageView;
}
-(UIView *)btnView {
if (!_btnView) {
_btnView = [[UIView alloc] initWithFrame:CGRectMake(0, 120, SCREENW, 30)];
_btnView.backgroundColor = [UIColor grayColor];
[self createButton:_btnView array:@[@"关注",@"群组",@"粉丝"] startTag:1000];
}
return _btnView;
}
//添加标题按钮
-(void)createButton:(UIView *)view array:(NSArray *)arr startTag:(NSInteger)tag{
CGFloat btnW = SCREENW / arr.count;
for (int i = 0; i < arr.count; i ++) {
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(i * btnW, 0, btnW, 30)];
[button setTitle:arr[i] forState:UIControlStateNormal];
[button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[button setTitleColor:[UIColor orangeColor] forState:UIControlStateSelected];
button.titleLabel.font = [UIFont systemFontOfSize:12];
[button addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
button.tag = tag + i;
[view addSubview:button];
}
view.userInteractionEnabled = YES;
}
//监听tableview的滑动,处理拉伸放大和悬浮条,对于导航条透明度没做处理
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat offSetY = scrollView.contentOffset.y;
if (offSetY < -OFFSETHEIGHT) {
self.navigationController.navigationBar.hidden = YES;
//处理拉伸放大效果
self.headerImageView.y = offSetY;
self.headerImageView.height = -offSetY;
//处理悬浮条
self.btnView.y = OFFSETHEIGHT-30 + (-offSetY - OFFSETHEIGHT);
}else if (offSetY>= -94) {
//处理悬浮条
self.btnView.y = 64;
[self.view addSubview:self.btnView];
self.navigationController.navigationBar.hidden = NO;
}else {
//处理悬浮条
self.btnView.y = OFFSETHEIGHT-30;
[self.headerImageView addSubview:self.btnView];
self.navigationController.navigationBar.hidden = YES;
}
}
