How to list out all the subviews in a uiviewcontro

Question

I want to list out all the subviews in a UIViewController. I tried self.view.subviews, but not all of the subviews are listed out, for instance, the subviews in the UITableViewCell are not found. Any idea?

Answer 1

Simple Swift example:

 var arrOfSub = self.view.subviews
 print("Number of Subviews: \(arrOfSub.count)")
 for item in arrOfSub {
    print(item)
 }

Answer 2

In my way, UIView's category or extension is much better than others and recursive is the key point to get all subviews

learn more:

https://github.com/ZhipingYang/XYDebugView

Objective-C

@implementation UIView (Recurrence)

- (NSArray<UIView *> *)recurrenceAllSubviews
{
    NSMutableArray <UIView *> *all = @[].mutableCopy;
    void (^getSubViewsBlock)(UIView *current) = ^(UIView *current){
        [all addObject:current];
        for (UIView *sub in current.subviews) {
            [all addObjectsFromArray:[sub recurrenceAllSubviews]];
        }
    };
    getSubViewsBlock(self);
    return [NSArray arrayWithArray:all];
}
@end

example

NSArray *views = [viewController.view recurrenceAllSubviews];

Swift 3.1

extension UIView {
    func recurrenceAllSubviews() -> [UIView] {
        var all = [UIView]()
        func getSubview(view: UIView) {
            all.append(view)
            guard view.subviews.count>0 else { return }
            view.subviews.forEach{ getSubview(view: $0) }
        }
        getSubview(view: self)
        return all
    }
}

example

let views = viewController.view.recurrenceAllSubviews()

directly, use sequence function to get all subviews

let viewSequence = sequence(state: [viewController.view]) { (state: inout [UIView] ) -> [UIView]? in
    guard state.count > 0 else { return nil }
    defer {
        state = state.map{ $0.subviews }.flatMap{ $0 }
    }
    return state
}
let views = Array(viewSequence).flatMap{ $0 }

Answer 3

- (NSString *)recusiveDescription:(UIView *)view
{
    NSString *s = @"";
    NSArray *subviews = [view subviews];
    if ([subviews count] == 0) return @"no subviews";

    for (UIView *subView in subviews) {
         s = [NSString stringWithFormat:@"<%@; frame = (%f %f : %f %f) \n ",NSStringFromClass([subView class]), subView.frame.origin.x, subView.frame.origin.y ,subView.frame.size.width, subView.frame.size.height];  
        [self recusiveDescription:subView];
    }
    return s;
}

Answer 4

This a rewriting of this answer:

You must first get the pointer/reference to the object you intend to print all its subviews. Sometimes you may find it easier to find that object by accessing it through its subview. Like po someSubview.superview. This will give you something like:

Optional<UIView>
  ▿ some : <FacebookApp.WhatsNewView: 0x7f91747c71f0; frame = (30 50; 354 636); clipsToBounds = YES; layer = <CALayer: 0x6100002370e0>>

• FaceBookApp is your app name
• WhatsNewView is the type of your superview
• 0x7f91747c71f0 is the pointer to the superview.

_{To print the superView, you must use breakpoints.}

---

Now to do this step you could just click on the 'view debug hierarchy'. No need for breakpoints

Then you could easily do:

po [0x7f91747c71f0 recursiveDescription]

which for me returned something like:

<FacebookApp.WhatsNewView: 0x7f91747c71f0; frame = (30 50; 354 636); clipsToBounds = YES; layer = <CALayer: 0x6100002370e0>>
   | <UIStackView: 0x7f91747c75f0; frame = (45 60; 264 93); layer = <CATransformLayer: 0x610000230ec0>>
   |    | <UIImageView: 0x7f916ef38c30; frame = (10.6667 0; 243 58); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x61000003b840>>
   |    | <UIStackView: 0x7f91747c8230; frame = (44.6667 58; 174.667 35); layer = <CATransformLayer: 0x6100006278c0>>
   |    |    | <FacebookApp.CopyableUILabel: 0x7f91747a80b0; baseClass = UILabel; frame = (44 0; 86.6667 16); text = 'What's New'; gestureRecognizers = <NSArray: 0x610000c4a770>; layer = <_UILabelLayer: 0x610000085550>>
   |    |    | <FacebookApp.CopyableUILabel: 0x7f916ef396a0; baseClass = UILabel; frame = (0 21; 174.667 14); text = 'Version 14.0.5c Oct 05, 2...'; gestureRecognizers = <NSArray: 0x610000c498a0>; layer = <_UILabelLayer: 0x610000087300>>
   | <UITextView: 0x7f917015ce00; frame = (45 183; 264 403); text = '   •   new Adding new feature...'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x6100000538f0>; layer = <CALayer: 0x61000042f000>; contentOffset: {0, 0}; contentSize: {264, 890}>
   |    | <<_UITextContainerView: 0x7f9170a13350; frame = (0 0; 264 890); layer = <_UITextTiledLayer: 0x6080002c0930>> minSize = {0, 0}, maxSize = {1.7976931348623157e+308, 1.7976931348623157e+308}, textContainer = <NSTextContainer: 0x610000117b20 size = (264.000000,340282346638528859811704183484516925440.000000); widthTracksTextView = YES; heightTracksTextView = NO>; exclusionPaths = 0x61000001bc30; lineBreakMode = 0>
   |    |    | <_UITileLayer: 0x60800023f8a0> (layer)
   |    |    | <_UITileLayer: 0x60800023f3c0> (layer)
   |    |    | <_UITileLayer: 0x60800023f360> (layer)
   |    |    | <_UITileLayer: 0x60800023eca0> (layer)
   |    | <UIImageView: 0x7f9170a7d370; frame = (-39 397.667; 36 2.33333); alpha = 0; opaque = NO; autoresize = TM; userInteractionEnabled = NO; layer = <CALayer: 0x60800023f4c0>>
   |    | <UIImageView: 0x7f9170a7d560; frame = (258.667 -39; 2.33333 36); alpha = 0; opaque = NO; autoresize = LM; userInteractionEnabled = NO; layer = <CALayer: 0x60800023f5e0>>
   | <UIView: 0x7f916ef149c0; frame = (0 587; 354 0); layer = <CALayer: 0x6100006392a0>>
   | <UIButton: 0x7f91747a8730; frame = (0 0; 0 0); clipsToBounds = YES; opaque = NO; layer = <CALayer: 0x610000639320>>
   |    | <UIButtonLabel: 0x7f916ef00a80; frame = (0 -5.66667; 0 16); text = 'See More Details'; opaque = NO; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x610000084d80>>

as you must have guessed my superview has 4 subviews:

• a stackView (the stackView itself has an image and another stackView(this stackView has 2 custom labels))
• a textView
• a view
• a button

This is fairly new to me, but has helped me debug a my views' frames (and text and type). One of my subviews wasn't showing up on the screen, so used recursiveDescription and I realized the width of my one of my subView's was 0... so I went corrected its constraints and the subview was appearing.

Answer 5

I wrote a category to list all views held by a view controller which inspired by the answers posted before.

@interface UIView (ListSubviewHierarchy)
- (NSString *)listOfSubviews;
@end

@implementation UIView (ListSubviewHierarchy)
- (NSInteger)depth
{
    NSInteger depth = 0;
    if ([self superview]) {
        deepth = [[self superview] depth] + 1;
    }
    return depth;
}

- (NSString *)listOfSubviews
{
    NSString * indent = @"";
    NSInteger depth = [self depth];

    for (int counter = 0; counter < depth; counter ++) {
        indent = [indent stringByAppendingString:@"  "];
    }

    __block NSString * listOfSubviews = [NSString stringWithFormat:@"\n%@%@", indent, [self description];

    if ([self.subviews count] > 0) {
        [self.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            UIView * subview = obj;
            listOfSubviews = [listOfSubviews stringByAppendingFormat:@"%@", [subview listOfSubviews]];
        }];
    }
    return listOfSubviews;
}
@end

To list all views held by a view controller, just NSLog("%@",[self listOfSubviews]), which self means the view controller itself. Though it's not quit efficient.

Plus, you can use NSLog(@"\n%@", [(id)self.view performSelector:@selector(recursiveDescription)]); to do the same thing, and I think it's more efficient than my implementation.

Answer 6

You have to recursively iterate the sub views.

- (void)listSubviewsOfView:(UIView *)view {

    // Get the subviews of the view
    NSArray *subviews = [view subviews];

    // Return if there are no subviews
    if ([subviews count] == 0) return; // COUNT CHECK LINE

    for (UIView *subview in subviews) {

        // Do what you want to do with the subview
        NSLog(@"%@", subview);

        // List the subviews of subview
        [self listSubviewsOfView:subview];
    }
}

---

As commented by @Greg Meletic, you can skip the COUNT CHECK LINE above.