Activity indicator (spinner) with UIActivityIndicatorView

Question

I have a tableView that loads an XML feed as follows:

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    if ([stories count] == 0) {         


        

Answer 1

I typically implement an NSTimer that will call my spinner method, which I fire off right before I go into doing the heavy work (the work that will typically block the main thread).

The NSTimer fires and my spinner method is called. When the main work is finished, I disable the spinner.

Code for that is like:

IBOutlet UIActiviyIndicatorView *loginIndicator;

{
    ...
    [loginIndicator startAnimating];

    [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(executeAuthenticationRequest) 
                                   userInfo:nil repeats:NO];   
    ...
}

- (void) executeAuthenticationRequest
{
    /* Simulate doing a network call. */
    sleep(3);

    [loginIndicator stopAnimating];

    ...
}

You can also do:

IBOutlet NSProgressIndicator *pIndicator;

Start:

[pIndicator startAnimation:self];
[pIndicator setHidden:NO];

And Stop:

[pIndicator stopAnimation:self];
[pIndicator setHidden:YES];