How to add a UIActivityIndicator View in my iOS app? - ios

Question

I don't know how to explain but... If you understand me when I say a "loading circle" perfect, I just want to do this
// Start loading in the middle of the screen frozing all interaction
for (int c = 0; c < ([barcos count] - 1); c++)
{
NSArray *datos = [[barcos objectAtIndex:c] componentsSeparatedByString:#";"];
NSString *nombreImagen = [datos objectAtIndex:2];
NSURL *accesoFtp = [NSURL URLWithString:[NSString stringWithFormat:#"%#/%#",urlFtp,nombreImagen]];
NSData *imagen = [NSData dataWithContentsOfURL:accesoFtp];
[imagen writeToFile:[[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Barcos/%#",nombreImagen]]] atomically:NO];
}
// Stop frozing all interaction and remove the loading circle
Probabbly I have to add a thread or something but I don't know how to do what I want exactly I hope you can help me, again. Thanks.
EDIT:
UIActivityIndicatorView *activityIndicator;
activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityIndicator.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
activityIndicator.center = self.view.center;
[self.view addSubview: activityIndicator];
activityIndicator.startAnimating;
dispatch_queue_t queue = dispatch_get_global_queue(0,0);
dispatch_async(queue, ^{
for (int c = 0; c < ([barcos count] - 1); c++)
{
NSArray *datos = [[barcos objectAtIndex:c] componentsSeparatedByString:#";"];
NSString *nombreImagen = [datos objectAtIndex:2];
NSURL *accesoFtp = [NSURL URLWithString:[NSString stringWithFormat:#"%#/%#",urlFtp,nombreImagen]];
NSData *imagen = [NSData dataWithContentsOfURL:accesoFtp];
[imagen writeToFile:[[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Barcos/%#",nombreImagen]]] atomically:NO];
}
dispatch_sync(dispatch_get_main_queue(), ^{
activityIndicator.stopAnimating;
});
});
Two things
1.- The activity indicator is too small but works, if I can to it bigger or same size but make darker the background would be better (Thanks!)
2.- I have a warning with startAnimating and stopAnimating "Property access result unused - getters should not be used for side effects"
Thanks =)

Answer 1

It can be done using MBProgressHUD
Also check this code:
//Show your activity indicator here
dispatch_queue_t queue = dispatch_get_global_queue(0,0);
dispatch_async(queue, ^{
for (int c = 0; c < ([barcos count] - 1); c++)
{
NSArray *datos = [[barcos objectAtIndex:c] componentsSeparatedByString:#";"];
NSString *nombreImagen = [datos objectAtIndex:2];
NSURL *accesoFtp = [NSURL URLWithString:[NSString stringWithFormat:#"%#/%#",urlFtp,nombreImagen]];
NSData *imagen = [NSData dataWithContentsOfURL:accesoFtp];
[imagen writeToFile:[[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Barcos/%#",nombreImagen]]] atomically:NO];
}
dispatch_sync(dispatch_get_main_queue(), ^{
//hide that activity indicator here
});
});
EDIT:
Never call methods like:
activityIndicator.startAnimating;
activityIndicator.stopAnimating;
These are used for calling setters and getters.
Change it to:
[activityIndicator startAnimating];
[activityIndicator stopAnimating];

Answer 2

You can use a UIActivityIndicatorView.
UIActivityIndicatorView *activityIndicator;
activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityIndicator.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
activityIndicator.center = self.view.center;
[self.view addSubview: activityIndicator];
Also, like shown by Midhun MP, you may have to use asynchronism to, for example, load data while your indicator is showing.

Answer 3

May be you can try Activity Indicator.

Answer 4

You can try using svprogresshud

Answer 5

You can alter the style of activityindicator,
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActionSheetStyleDefault];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActionSheetStyleBlackOpaque];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActionSheetStyleBlackTranslucent];
use any of these styles.
And This link can help to solve your second issue
xCode "Property access results unused - getters should not be used for side effects"
SOLUTION:
instead of using activityIndicator.startAnimating; and activityIndicator.stopAnimating
use [activityIndicator startAnimating]; and [activityIndicator stopAnimating];

Answer 6

For changing the size of the activity indicator:
activityIndicator.frame = CGRectMake(0.0, 0.0, 80.0, 80.0);
activityIndicator.transform = CGAffineTransformMakeScale(1.75, 1.75);
By the way, if you are populating a tableview, you may consider enabling the user interaction at the same time you launch the activity indicator:
[activityIndicator startAnimating];
tableView.userInteractionEnabled = NO;
and restoring it after:
[self.tableView reloadData];
[activityIndicator stopAnimating];
tableView.userInteractionEnabled = YES;