How can I loop through all subviews of a UIView, and their subviews and their subviews

iphone objective-c loops uiview subview

87,554

Solution 1

Use recursion:

// UIView+HierarchyLogging.h
@interface UIView (ViewHierarchyLogging)
- (void)logViewHierarchy;
@end

// UIView+HierarchyLogging.m
@implementation UIView (ViewHierarchyLogging)
- (void)logViewHierarchy
{
    NSLog(@"%@", self);
    for (UIView *subview in self.subviews)
    {
        [subview logViewHierarchy];
    }
}
@end

// In your implementation
[myView logViewHierarchy];

Solution 2

Well here is my solution using recursion and a wrapper(category/extension) for the UIView class.

// UIView+viewRecursion.h
@interface UIView (viewRecursion)
- (NSMutableArray*) allSubViews;
@end

// UIView+viewRecursion.m
@implementation UIView (viewRecursion)
- (NSMutableArray*)allSubViews
{
   NSMutableArray *arr=[[[NSMutableArray alloc] init] autorelease];
   [arr addObject:self];
   for (UIView *subview in self.subviews)
   {
     [arr addObjectsFromArray:(NSArray*)[subview allSubViews]];
   }
   return arr;
}
@end

Usage : Now you should be looping through all the sub views and manipulate them as needed.

//disable all text fields
for(UIView *v in [self.view allSubViews])
{
     if([v isKindOfClass:[UITextField class]])
     {
         ((UITextField*)v).enabled=NO;
     }
}

Solution 3

Here's another Swift implementation:

extension UIView {
    var allSubviews: [UIView] {
        return self.subviews.flatMap { [$0] + $0.allSubviews }
    }
}

Solution 4

A solution in Swift 3 that gives all subviews without including the view itself:

extension UIView {
var allSubViews : [UIView] {

        var array = [self.subviews].flatMap {$0}

        array.forEach { array.append(contentsOf: $0.allSubViews) }

        return array
    }
}

Solution 5

Just found an interesting way to do this through the debugger:

http://idevrecipes.com/2011/02/10/exploring-iphone-view-hierarchies/

references this Apple Technote:

https://developer.apple.com/library/content/technotes/tn2239/_index.html#SECUIKIT

Just make sure your debugger is paused (either set a break point of pause it manually) and you can ask for the recursiveDescription.

View more solutions

87,554

Author by

123hal321

Updated on September 25, 2020

Comments

123hal321 over 3 years

How can I loop through all subviews of a UIView, and their subviews and their subviews?
ivanzoid almost 13 years

Note there are memory leak in allSubViews function: you must either create array as [[[NSMutableArray alloc] init] autorelease] or as [NSMutableArray array] (which is the same).
docchang over 12 years

Is there a way to pass a function in the logViewHierarchy? That way it can suit your needs at different times.
Ole Begemann over 12 years

@docchang: Obj-C blocks are a great fit for that use case. You pass a block to the method, execute the block and pass it down the hierarchy with each method call.
Eric G almost 12 years

Looks like I made a very similar solution as the one you proposed here. I went ahead and posted it on github in case others might find it useful. Here's my answer w/ the link :) stackoverflow.com/a/10440510/553394
Dimitris almost 12 years

By "a wrapper for UIView" you actually mean "a category for UIView".
RamaKrishna Chunduri almost 12 years

Yes Dimitris, i meant category.
jaredsinclair almost 11 years

Nice. I posted a snippet below that adds whitespace indentation to this technique.
Admin about 10 years

How could I add a way to halt the recursion from within the block? Say I'm using this to locate a specific view, once I've found it I'd like to stop there and not continue searching the rest of the view hierarchy.
Ashish Ramani over 8 years

helpful solution and time saver.. thanx 1 plus for u
Jed Fox over 7 years

Please use the edit link explain how this code works and don't just give the code, as an explanation is more likely to help future readers. See also How to Answer. source
Jed Fox over 7 years

Please see my comment above.
Rahul Patel over 6 years

What is need of ".flatMap {$0}" in this line "var array = [self.subviews].flatMap {$0}" ?
ielyamani over 6 years

@RahulPatel it removes nil elements from an array, for safety when calling allSubViews on subviews.
Balaji Ramakrishnan about 5 years

Simple and Best one
SundialSoft over 4 years

can you explain where the 'empty area' is ? I have tried all around the Xcode window once the breakpoint has fired but can't find where to input the string
Alexander Langer almost 2 years

Sexy code. Made my day