How to remove specific subview?

Question

I've added subview (ViewController) to my ViewController:

Location *location = [[Location alloc] initWithNibName:@"Location" bundle:[NSBundle mainBundle]];
[self.subView addSubview:location.view];

How can I latter remove this subview?

I know that for removing all subviews is:

for (UIView *subview in [self.view subviews]) {

  [subview removeFromSuperview];

}

Answer 1

Quick and dirty: Give your view a tag, so you can later identify it:

Location *location = [[Location alloc] initWithNibName:@"Location" bundle:[NSBundle mainBundle]];
UIView *viewToAdd = location.view;
viewToAdd.tag = 17; //you can use any number you like
[self.view addSubview:viewToAdd];

Then, to remove:

UIView *viewToRemove = [self.view viewWithTag:17];
[viewToRemove removeFromSuperview];

---

A cleaner, faster, easier to read and to maintain alternative would be to create a variable or property to access the view:

In the interface:

@property (nonatomic, weak) UIView *locationView;

In the implementation:

Location *location = [[Location alloc] initWithNibName:@"Location" bundle:[NSBundle mainBundle]];
UIView *viewToAdd = location.view;
self.locationView = viewToAdd;
[self.view addSubview:viewToAdd];

Then, to remove:

[self.locationView removeFromSuperview];

---

That said, heed the warnings from commenters about playing with other ViewControllers' Views. Read up on ViewController containment if you want to do it.

Answer 2

Create an ivar that either gives you a reference to the new viewController or just the view. I'll go for the viewController here

Add a property and synthesize it

// .h
@property (nonatomic, strong) Location *location;

// .m
@synthesize location = _location;

Now when you create location set the ivar

Location *location = [[Location alloc] initWithNibName:@"Location" bundle:[NSBundle mainBundle]];
self.location = location;

[self.subView addSubview:location.view];

Now later to remove it

[self.location.view removeFromSuperview];

---

Side note

Generally it is a painful path to be adding a view controller's view to the view of another like this. For some light reading about this see Abusing UIViewControllers

Your naming of Location is probably not excellent, it may be more appropriate to call it something like LocationViewController or similar. Consistant naming in this way allows anyone else (or future you) to be able to easily read and grasp that this is a viewController without opening up the header.

Answer 3

You could simply set a unique tag to your view that identifies it. And then when you want to remove it. Use the viewWithTag:(NSInteger)tag method to get it back and remove only this one.

Location *location = [[Location alloc] initWithNibName:@"Location" bundle:[NSBundle mainBundle]];
location.tag = 8001; // 8001 is an exemple
[self.subView addSubview:location.view];

And then

UIView * v = [self.subView viewWithTag:8001];
if (nil != v) {
    [v removeFromSuperview];
}