IOS - Have UITableViewCells scroll over UIView (like the shazam app) - ios

Question

I have a UIView above my UITableView. When the user scrolls down I want the UIView to stay in place at the top of the screen and have the cells scroll over it. The first page of the Shazam app does what I want.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (self.tableView.contentOffset.y > 0) {
CGRect newframe = self.publicTopView.frame;
newframe.origin.y = -self.tableView.contentOffset.y;
self.publicTopView.frame = newframe;
}
}
This is what I've tried so far, but it doesn't do anything. Thanks

Answer 1

I would set the tableView.backgroundView to your view, and then set your cells to be clear (or whatever transparency you like). This will allow the cells to move over the view.

Answer 2

You need to have a scrollView with a transparent background. Then add a subview to it that is not transparent and offset down a bit. Here's an overkill example. The TextureView is just so you can see that the background isn't moving.
#import "ViewController.h"
#interface TextureView : UIView
#end
#implementation TextureView
-(void)drawRect:(CGRect)rect{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginPath(context);
CGContextMoveToPoint(context, 0, 0);
CGContextAddLineToPoint(context, rect.size.width, rect.size.height);
CGContextMoveToPoint(context, 0, rect.size.height);
CGContextAddLineToPoint(context, rect.size.width, 0);
CGContextSetStrokeColorWithColor(context, [[UIColor whiteColor]CGColor]);
CGContextSetLineWidth(context, 8);
CGContextStrokePath(context);
}
#end
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
CGRect scrollViewFrame = self.view.frame;
CGFloat sectionHeight = 300;
int numberSections = 3;
CGFloat clearSpaceAtTop = 300;
CGRect sectionsViewFrame = CGRectMake(0, clearSpaceAtTop, scrollViewFrame.size.width, sectionHeight * numberSections);
CGSize contentSize = CGSizeMake(scrollViewFrame.size.width, CGRectGetMaxY(sectionsViewFrame));
TextureView *backGroundView = [[TextureView alloc]initWithFrame:scrollViewFrame];
backGroundView.backgroundColor = [UIColor blueColor];
[self.view addSubview:backGroundView];
UIScrollView *scrollView = [[UIScrollView alloc]initWithFrame:scrollViewFrame];
scrollView.contentSize = contentSize;
scrollView.backgroundColor = [UIColor clearColor];
[self.view addSubview:scrollView];
UIView *sectionViewsParent = [[UIView alloc]initWithFrame:sectionsViewFrame];
sectionViewsParent.backgroundColor = [UIColor lightGrayColor];
[scrollView addSubview:sectionViewsParent];
NSArray *colors = #[[UIColor redColor],[UIColor greenColor],[UIColor purpleColor]];
CGFloat spacer = 4;
CGRect colorViewFrame = CGRectMake(0, 0, sectionsViewFrame.size.width, sectionHeight - spacer);
for (UIColor *color in colors){
UIView *sectionView = [[UIView alloc]initWithFrame:colorViewFrame];
sectionView.backgroundColor = color;
[sectionViewsParent addSubview:sectionView];
colorViewFrame.origin.y += sectionHeight;
}
}
#end

Answer 3

If the UIView instance is called iconView, the UITableView instance is called tableView,
If your view controller is UIViewController.
[self.view addSubview:iconView];
[self.view addSubview:tableView];
//and you need set tableView.background to transparent.
If your view controller is UITableViewController, read this question:
UITableViewController Background Image

Answer 4

basically all you have to do is to use UIScrollView's contentInset property
let topInset = topViewHeight.constant //based on your needs
sampleTableView.contentInset = UIEdgeInsets(top: topInset, left: 0, bottom: 0, right: 0)
see my github sample here