How to pass an activity indicator between methods/

Question

Hello I have a problem with an added subview. I have this code in method1:

UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]
                                    initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
spinner.center = CGPointMake(160, 500);
spinner.hidesWhenStopped = YES;
[self.view addSubview:spinner];
[spinner startAnimating];

and I want to add

[spinner stopAnimating]

on another method2.

How do I do so?

Create a property for the activity indicator and then control it from whichever method you want. — sooper, May 15 '14 at 23:02
@user3642828 If you need help writing the code for an instance variable or a property then SO isn't the proper website for you yet. Please spend some time working with tutorials on the basics of the Objective-C programming language. It is important to learn the basics first. — rmaddy, May 15 '14 at 23:07

score 2 · Accepted Answer · answered May 15 '14 at 23:08

In your .m file (no need to do this in .h unless you need to do this from another class):

@interface MyClass ()

@property (strong, nonatomic) UIActivityIndicatorView *spinner;

@end

@implementation MyClass

- (void)someMethod
{
    // where you were calling the code from your post, do this:
    self.spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    self.spinner.center = CGPointMake(160, 500);
    self.spinner.hidesWhenStopped = YES;
    [self.view addSubview:self.spinner];
    [self.spinner startAnimating];
}

- (void)someOtherMethod
{
    [self.spinner stopAnimating];
}

score 1 · Answer 2 · answered May 15 '14 at 23:05

The problem is that you set up the spinner in your code without keeping a reference to it. Thus, another method can't find it. You have two choices:

Assign spinner to an instance variable when you create it so that another method can use that instance variable to access the spinner
Give spinner a tag so that another method can find it as a subview of your view by its tag

How to pass an activity indicator between methods/

2 Answers2