How to set iPhone UIView z index?

Question

I want to move one view on top of another, how can I know the z index of the view, and how to move on to top?

score 344 · Answer 1 · edited May 23 '17 at 11:47

344

You can use the zPosition property of the view's layer (it's a CALayer object) to change the z-index of the view.

theView.layer.zPosition = 1;

As Viktor Nordling added, "big values are on top. You can use any values you want, including negative values." The default value is 0.

You need to import the QuartzCore framework to access the layer. Just add this line of code at the top of your implementation file.

#import "QuartzCore/QuartzCore.h"

edited May 23 '17 at 11:47

Community

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answered Jan 08 '11 at 01:49

Daniel Node.js

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Just as a helper, big values are "on top". You can use any values you want, including negative values. – Viktor Nordling Jun 09 '12 at 13:08
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This solution is better in case you want your view to be always on top. Just set zPosition to MAXFLOAT – Muhammad Hassan Nasr Nov 22 '12 at 17:42
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I've just learned that the zPosition of the layer, and the UIView's input handler, are on two different Z-orders. It's really odd when your clicks "pass through" – Stephen J Dec 11 '12 at 22:07
does the views' superview have to be the same in order to make `zPosition` works? – Hlung Sep 15 '13 at 17:15
Just got weird behaviour with transparency and rendering, my on-top view was blinking with some chunks of UILabel at the bottom, the thing was that I used CGFLOAT_MAX for zPosition. MAXFLOAT fixed this for me. – MANIAK_dobrii Feb 03 '15 at 14:05
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I noticed that, even though the view is on top, clicks go through it to objects underneath. This ought to be considered a bug. I am trying to find a general way to avoid that problem, without having to explicitly disable user interactions of any views that happen to be underneath. – Bruce Patin Aug 12 '15 at 15:02
@BrucePatin yes it seems the responder chain is not affected by this, did you find a solution? I need the view on top to be interactive :/ – User Jun 15 '16 at 21:33
Using `_view.Layer.ZPosition = float.MinValue;` did not put the view behind items on my storyboard. I had to use `View.SendSubviewToBack(_view);` for that. – Joseph Feb 28 '18 at 23:13

score 286 · Accepted Answer · answered Jan 11 '11 at 22:42

UIView siblings are stacked in the order in which they are added to their superview. The UIView hierarchy methods and properties are there to manage view order. In UIView.h:

@property(nonatomic,readonly) UIView *superview;
@property(nonatomic,readonly,copy) NSArray *subviews;

- (void)removeFromSuperview;
- (void)insertSubview:(UIView *)view atIndex:(NSInteger)index;
- (void)exchangeSubviewAtIndex:(NSInteger)index1 withSubviewAtIndex:(NSInteger)index2;

- (void)addSubview:(UIView *)view;
- (void)insertSubview:(UIView *)view belowSubview:(UIView *)siblingSubview;
- (void)insertSubview:(UIView *)view aboveSubview:(UIView *)siblingSubview;

- (void)bringSubviewToFront:(UIView *)view;
- (void)sendSubviewToBack:(UIView *)view;

The sibling views are ordered back to front in the subviews array. So the topmost view will be:

[parentView.subviews lastObject];

and bottom view will be:

[parentView.subviews objectAtIndex:0];

Like Kolin Krewinkel said, [parentView bringSubviewToFront:view] will bring the view to the top, but this is only the case if the views are all siblings in the hierarchy.

score 127 · Answer 3 · edited Jun 20 '20 at 09:12

IB and Swift

Given the flowing layout where yellow is the superview and red, green, and blue are sibling subviews of yellow,

the goal is to move a subview (let's say green) to the top.

In Interface Builder

In the Interface Builder all you need to do is drag the view you want showing on the top to the bottom of the list in the Documents Outline.

Alternatively, you can select the view and then in the menu go to Editor > Arrange > Send to Front.

In Swift

There are a couple of different ways to do this programmatically.

Method 1

yellowView.bringSubviewToFront(greenView)

This method is the programmatic equivalent of the IB answer above.
It only works if the subviews are siblings of each other.
An array of the subviews is contained in yellowView.subviews. Here, bringSubviewToFront moves the greenView from index 0 to 2. This can be observed with
```
  print(yellowView.subviews.indexOf(greenView))
```

Method 2

greenView.layer.zPosition = 1

This method just moves the 3D position of the layer higher (closer to the user) on the z-axis. Since the default is 0 for all the other views, the result is that the greenView looks like it is on top. However, it still remains at index 0 of the yellowView.subviews array. This can cause some unexpected results, though, because things like tap events will still go first to the view with the highest index number. For that reason, it might be better to go with Method 1 above.
The zPosition could be set to CGFloat.greatestFiniteMagnitude (CGFloat(FLT_MAX) in older versions of Swift) to ensure that it is on top.

thanks for this... i spent 8 hours trying to figure this out. yellowView.bringSubviewToFront(greenView) worked perfectly. — MizAkita, Mar 03 '16 at 21:45
Interestingly, **container views** do not respect this! You have to manually move them in code, it seems. — Fattie, Jun 08 '16 at 17:26
Thank you for the explanation regarding the difference of moving the actual index or changing the z-index, which seems to be more like a cosmetic change. — Jan, Dec 31 '20 at 10:16

score 75 · Answer 4 · edited Nov 25 '15 at 21:53

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[parentView bringSubviewToFront:view] ;

edited Nov 25 '15 at 21:53

itsji10dra

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answered Jan 08 '11 at 01:54

Kolin Krewinkel

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score 19 · Answer 5 · answered Feb 16 '12 at 12:48

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If you want to do this through XCode's Interface Builder, you can use the menu options under Editor->Arrangement. There you'll find "Send to Front", "Send to Back", etc.

answered Feb 16 '12 at 12:48

larspars

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What if the options from Arrange are disabled? – mr5 Feb 12 '20 at 10:31

score 9 · Answer 6 · answered Jul 15 '16 at 16:31

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Within the view you want to bring to the top... (in swift)

superview?.bringSubviewToFront(self)

answered Jul 15 '16 at 16:31

Carter Medlin

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btnDOWN.superview?.bringSubview(toFront: btnDOWN) – Criss Dec 01 '18 at 16:10

score 7 · Answer 7 · answered Mar 22 '19 at 07:44

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We can use zPosition in ios

if we have a view named salonDetailView eg : @IBOutlet weak var salonDetailView: UIView!

In my case see the image

and have UIView for GMSMapView eg : @IBOutlet weak var mapViewUI: GMSMapView!

To show the View salonDetailView upper of the mapViewUI

use zPosition as below

salonDetailView.layer.zPosition = 1

answered Mar 22 '19 at 07:44

abhijith k

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please post photos and code directly here in your answer, to make it easier for OP to get it. – skratchi.at Mar 22 '19 at 08:03
as a beginner, StackOverflow will not allow me to do that sorry. you can check the problem image https://i.stack.imgur.com/d9Cx3.png – abhijith k Mar 22 '19 at 12:05
Worked like a charm on my CAShapeLayers in macos! – SouthernYankee65 Jun 21 '22 at 21:17

score 4 · Answer 8 · answered Dec 18 '13 at 08:59

If you are using cocos2d, you may see an issue with [parentView bringSubviewToFront:view], at least it was not working for me. Instead of bringing the view I wanted to the front, I send the other views back and that did the trick.

[[[CCDirector sharedDirector] view] sendSubviewToBack:((UIButton *) button)];

score 0 · Answer 9 · answered Oct 13 '19 at 08:02

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Or use this

- (void)insertSubview:(UIView *)view belowSubview:(UIView*)siblingSubview;

as per here

answered Oct 13 '19 at 08:02

Peter

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How to set iPhone UIView z index?

9 Answers9

In Interface Builder

In Swift

Linked