When my app gets back to its root view controller, in the viewDidAppear: method I need to remove all subviews.

How can I do this?

14 Answers 11

up vote 539 down vote accepted

Edit: With thanks to cocoafan: This situation is muddled up by the fact that NSView and UIView handle things differently. For NSView (desktop Mac development only), you can simply use the following:

[someNSView setSubviews:[NSArray array]];

For UIView (iOS development only), you can safely use makeObjectsPerformSelector: because the subviews property will return a copy of the array of subviews:

[[someUIView subviews]
 makeObjectsPerformSelector:@selector(removeFromSuperview)];

Thank you to Tommy for pointing out that makeObjectsPerformSelector: appears to modify the subviews array while it is being enumerated (which it does for NSView, but not for UIView).

Please see this SO question for more details.

Note: Using either of these two methods will remove every view that your main view contains and release them, if they are not retained elsewhere. From Apple's documentation on removeFromSuperview:

If the receiver’s superview is not nil, this method releases the receiver. If you plan to reuse the view, be sure to retain it before calling this method and be sure to release it as appropriate when you are done with it or after adding it to another view hierarchy.

9 upvote
  flag
Are you sure this is safe? It mutates the list while iterating it, and I'm unable to find a definitive statement in Apple's documentation. – Tommy
8 upvote
  flag
@Tommy: That is a good point. Some Googling turned up the answer: UIView returns a copy of the subviews mutable array, so this code just works. Completely different story on the desktop, where the same code will throw an exception. See //allinonescript.com/questions/4665179/… – e.James
upvote
  flag
@Tommy: I have updated my answer accordingly. Thank you for catching that! – e.James
3 upvote
  flag
UIView does not respond to setSubviews:, does it? – cocoafan
upvote
  flag
@cocoafan: It looks like you are right. You can only set the subviews from within subclasses of UIView. It is NSView that allows setting them externally. – e.James
upvote
  flag
Couldn't find a way to do this in Swift – Van Du Tran
4 upvote
  flag
the Xamarin way : someUIView.Subviews.All(p => p.RemoveFromSuperview); – Benoit Jadinon
upvote
  flag
Good answer, Slightly different way: create a UIView category and implement some -(void)removeSubviews method. Same mechanism, but prettier code. – AzaFromKaza
3 upvote
  flag
@BenoitJadinon - won't compile - you appear to mean abusing All to perform ForEach, so someUIView.Subviews.All( v => { v.RemoveFromSuperview(); return true; } );. IMHO cleaner to say what you mean: someUIView.Subviews.ToList().ForEach( v => v.RemoveFromSuperview() );. – ToolmakerSteve

Get all the subviews from your root controller and send each a removeFromSuperview:

NSArray *viewsToRemove = [self.view subviews];
for (UIView *v in viewsToRemove) {
    [v removeFromSuperview];
}
upvote
  flag
+1 and thank you. I should have also used self.view as you have. – e.James
1 upvote
  flag
why not!? for (UIView *v in [self.view subviews]) its easier – Frade
3 upvote
  flag
@Frade It's much clearer and more verbose the way he did it. Verbose and readability > saving keystrokes – taylorcressy
25 upvote
  flag
@taylorcressy You should have said "readability is more important than saving keystrokes" instead of "readability > saving keystrokes" and then your comment would be more readable. :-) – arlomedia

If you want to remove all the subviews on your UIView (here yourView), then write this code at your button click:

[[yourView subviews] makeObjectsPerformSelector: @selector(removeFromSuperview)];
12 upvote
  flag
Welcome to Stack Overflow! Would you consider adding some narrative to explain why this code works, and what makes it an answer to the question? This would be very helpful to the person asking the question, and anyone else who comes along. Additionally, the already-accepted answer includes code that is essentially the same as this. – Andrew Barber
3 upvote
  flag
How could this help more so than the accepted answer: It's identical. Why write this? – Rambatino

For ios6 using autolayout I had to add a little bit of code to remove the constraints too.

NSMutableArray * constraints_to_remove = [ @[] mutableCopy] ;
for( NSLayoutConstraint * constraint in tagview.constraints) {
    if( [tagview.subviews containsObject:constraint.firstItem] ||
       [tagview.subviews containsObject:constraint.secondItem] ) {
        [constraints_to_remove addObject:constraint];
    }
}
[tagview removeConstraints:constraints_to_remove];

[ [tagview subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];

I'm sure theres a neater way to do this, but it worked for me. In my case I could not use a direct [tagview removeConstraints:tagview.constraints] as there were constraints set in XCode that were getting cleared.

In order to remove all subviews Syntax :

- (void)makeObjectsPerformSelector:(SEL)aSelector;

Usage :

[self.View.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];

This method is present in NSArray.h file and uses NSArray(NSExtendedArray) interface

In order to remove all subviews from superviews:

NSArray *oSubView = [self subviews];
for(int iCount = 0; iCount < [oSubView count]; iCount++)
{
    id object = [oSubView objectAtIndex:iCount];
    [object removeFromSuperview];
    iCount--;
}
upvote
  flag
Couple of major mistakes here @Pravin. First, you'd need 'object' to be defined as a UIView* otherwise you'd get a compiler error with [object removeFromSuperview]. Second, your for loop is already decrementing iCount so you are skipping an extra one with your iCount-- line. And finally, there are two working and correct approaches above and yours is neither more elegant nor faster. – amergin
5 upvote
  flag
each iteration you do iCount++ and iCount--, leaving the index the same, so it will be an infinite loop if [oSubView count]>0. This is definitely buggy and NOT USABLE code. – Daniel

When removing all the subviews, it is a good idea to start deleting at the end of the array and keep deleting until you reach the beginning. This can be accomplished with this two lines of code:

for (int i=mySuperView.subviews.count-1; i>=0; i--)
        [[mySuperView.subviews objectAtIndex:i] removeFromSuperview];

SWIFT 1.2

for var i=mySuperView.subviews.count-1; i>=0; i-- {
    mySuperView.subviews[i].removeFromSuperview();
}

or (less efficient, but more readable)

for subview in mySuperView.subviews.reverse() {
    subview.removeFromSuperview()
}

NOTE

You should NOT remove the subviews in normal order, since it may cause a crash if a UIView instance is deleted before the removeFromSuperview message has been sent to all objects of the array. (Obviously, deleting the last element would not cause a crash)

Therefore, the code

[[someUIView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];

should NOT be used.

Quote from Apple documentation about makeObjectsPerformSelector:

Sends to each object in the array the message identified by a given selector, starting with the first object and continuing through the array to the last object.

(which would be the wrong direction for this purpose)

upvote
  flag
Can you please make an example of what you are referring to ? Don't know what are you referring to as "element" And how would this elements be removed before calling removeFromSuperView ? – the Reverend
upvote
  flag
with element I meant UIView instance (edited). – Daniel
upvote
  flag
But how can an instance of UIView be deleted while calling this method ? Do you mean removed from the subview array ? – the Reverend
upvote
  flag
When removeFromSuperview finishes, the UIView will be removed from the array, and if there are no other living instances with a strong relation to the UIView, the UIView will also be deleted. This may cause an out of bound exception. – Daniel
1 upvote
  flag
Gotcha! Thank you. I think you are getting a copy of the subviews array on IOS. In any case, it would be a good idea to make a copy yourself if you want to remove subviews. – the Reverend
upvote
  flag
@simpleBob - did you read the comments written in 2011 on the accepted answer? According to those comments, on iOS, [yourView subviews] returns a COPY of the array, therefore is safe. (NOTE that on OSX, what you say is correct.) – ToolmakerSteve

In Swift you can use a functional approach like this:

view.subviews.forEach { $0.removeFromSuperview() }

Note: This code is updated to Swift 2.1+ syntax.

As a comparison, the imperative approach would look like this:

for subview in view.subviews {
    subview.removeFromSuperview()
}

These code snippets only work in iOS / tvOS though, things are a little different in OS X.

4 upvote
  flag
(subviews as [UIView]).map { $0.removeFromSuperview() } – DeFrenZ
5 upvote
  flag
it's not functional since a function returns a value and this just discards the result of the .map. this is a pure side effect and is better handled like this: view.subviews.forEach() { $0.removeFromSuperview() } – Martin Algesten
1 upvote
  flag
You are right, Martin, I agree with you. I just didn't know there was a forEach() method on Arrays. When was it added or did I just oversee it? I've updated my answer! – Dschee

If you're using Swift, it's as simple as:

subviews.map { $0.removeFromSuperview }

It's similar in philosophy to the makeObjectsPerformSelector approach, however with a little more type safety.

Using Swift UIView extension:

extension UIView {
    func removeAllSubviews() {
        for subview in subviews {
            subview.removeFromSuperview()
        }
    }
}

Try this way swift 2.0

view.subviews.forEach { $0.removeFromSuperview() }
upvote
  flag
This solution was already provided: //allinonescript.com/a/27117440/1974224 – Cristik
2 upvote
  flag
Don't you see the date answer date i am earlier? Why not paste my answer link into that answer? – William Hu
1 upvote
  flag
Right... the answer was posted before yours however the forEach based solution was added after yours, I missed that. Apologies. – Cristik

In monotouch / xamarin.ios this worked for me:

SomeParentUiView.Subviews.All(x => x.RemoveFromSuperview);

In objective-C, go ahead and create a category method off of the UIView class.

- (void)removeAllSubviews
{
    for (UIView *subview in self.subviews)
        [subview removeFromSuperview];
}

Use the Following code to remove all subviews.

for (UIView *view in [self.view subviews]) 
{
 [view removeFromSuperview];
}

Not the answer you're looking for? Browse other questions tagged or ask your own question.