unable to show activity indicator iOS - ios

Question

i am trying to show UIActivityIndicator on viewDidLoad of a screen. its working in another project but not sure why it's not displayed here.
I am calling the showSplashScreen fromviewDidLoad of other screen.
+(void) showSplashScreen
{
UIView *mainScreen = [[[UIApplication sharedApplication]delegate]window];
UIView *windowBlocker = [[UIView alloc]initWithFrame:mainScreen.frame];
windowBlocker.tag = 999;
windowBlocker.backgroundColor = [UIColor clearColor];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake((mainScreen.frame.size.width), (mainScreen.frame.size.height), 50, 50)];
imageView.layer.backgroundColor=[[UIColor colorWithRed:200 green:0 blue:0 alpha:0.5] CGColor];
imageView.layer.cornerRadius=10;
imageView.layer.masksToBounds = YES;
[windowBlocker addSubview:imageView];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
[windowBlocker addSubview:spinner];
spinner.center = mainScreen.center;
[spinner startAnimating];
}
nothing happens. Any idea? I am trying for iPad.

Answer 1

UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
[imageView addSubview:spinner];
spinner.center = mainScreen.center;
[windowBlocker addSubview:imageView];
[self.view addSubview: mainScreen];
[spinner startAnimating];

Answer 2

//Yoy forget to add windowBlocker in mainview
[Self.view addSubview:windowBlocker];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
spinner.center = mainScreen.center;
[spinner startAnimating];
[windowBlocker addSubview:spinner];
//Try this code

Answer 3

looks like the issue is that you haven't added windowBlocker to the screen.
try:
[mainScreen addSubview:windowBlocker];

Answer 4

-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self performSelector:#selector(addSplash) withObject:nil afterDelay:0.5];
}
-(void)addSplash {
[[self class] showSplashScreen];
}
+(void) showSplashScreen
{
UIView *mainScreen = [[[UIApplication sharedApplication]delegate]window];
UIView *windowBlocker = [[UIView alloc]initWithFrame:mainScreen.frame];
windowBlocker.tag = 999;
windowBlocker.backgroundColor = [UIColor redColor];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake((mainScreen.frame.size.width), (mainScreen.frame.size.height), 50, 50)];
imageView.layer.backgroundColor=[[UIColor colorWithRed:200 green:0 blue:0 alpha:0.5] CGColor];
imageView.layer.cornerRadius=10;
imageView.layer.masksToBounds = YES;
[windowBlocker addSubview:imageView];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
[windowBlocker addSubview:spinner];
spinner.center = mainScreen.center;
[spinner startAnimating];
[[[[UIApplication sharedApplication]delegate]window] addSubview:windowBlocker];
}
As I added some delay with 0.5 because when i called function in ViewDidLoad orViewWillAppear some reason view not initaliaze yet so i provide some delay or you can use the viewDidAppear for as an option of this situation like and only this function and remove viewWillAppear and addSplash and add only this
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[[self class] showSplashScreen];
}

Answer 5

Change this ... it works for you
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
spinner.color=[UIColor greenColor];
spinner.center = self.view.center;
[spinner startAnimating];
[windowBlocker addSubview:spinner];