Question

I have an imaged name Default.png. This will load when the application is launching. Now i need to add an activity indicator to it. So it will spin and make the app look nice.

We know that we can’t add any UI Components when the app is loading. So i thought to add the UIActivityIndicator in the didFinishLaunchingWithOptions method in the App delegate.

These are the steps i followed.
i added a view
added the default.png
added activity indicator

then

[window addSubView:view];

But nothing hapence.

Help how to write the code for this ?

Answer 1

You’re on the right track, but you do need to add another UIView to your window (not another UIViewContoller, necessarily) temporarily. I do this sort of thing often. Here’s some code that would be appropriate for your applicationDidFinishLaunching:withOptions: method:

[window makeKeyAndVisible]
...

// Create and show an overlay view with a spinner
UIImage *defaultImage = [UIImage imageNamed:@"Default.png"];
UIImageView *imageView = [[UIImageView alloc] initWithImage:defaultImage];
UIActivityIndicatorView *spinner = [[UIActivityIndicatorView alloc]
            initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
// Position the spinner appropriately for our splash image so it's not obscured
CGRect frame = spinner.frame;
frame.origin.x = imageView.frame.size.width / 2 - frame.size.width / 2;
frame.origin.y = imageView.frame.size.height / 5 * 4 - frame.size.height / 2;
spinner.frame = frame;
[spinner startAnimating];
[spinner setHidesWhenStopped:YES];

startupView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)];
[startupView addSubview:imageView];
[imageView release];
[startupView addSubview:spinner];
[spinner release];
[window addSubview:startupView];

The ivar startupView belongs to the app delegate, and later in the startup sequence another method removes it gracefully by fading it from view:

UIActivityIndicatorView *spinner = [[startupView subviews] lastObject];
[spinner stopAnimating];
[UIView animateWithDuration:1.0
                      delay:0
                    options:UIViewAnimationOptionCurveLinear
                 animations:^(void) {
                     startupView.alpha = 0.0;
                 } completion:^(BOOL finished) {
                     [startupView removeFromSuperview];
                     [startupView release];
                 }];

It’s worth mentioning that splash screens like this are not the “recommended” startup screen in Apple’s view. But they do not seem to reject apps that have them.