iOS : ModalView with background transparent?

Use following snippet to do it on iOS 8 onwards:

For Objective C:

UIViewController *walkThru = [self.storyboard   instantiateViewControllerWithIdentifier:@"WalkThroughScene"];
walkThru.providesPresentationContextTransitionStyle = YES;
walkThru.definesPresentationContext = YES;
[walkThru setModalPresentationStyle:UIModalPresentationOverCurrentContext];
[self.navigationController presentViewController:walkThru animated:YES completion:nil];

For Swift 2 :

let viewController : XYZViewController =     self.storyboard!.instantiateViewControllerWithIdentifier(“XYZIdentifier”) as! XYZViewController
viewController.providesPresentationContextTransitionStyle = true
viewController.definesPresentationContext = true
viewController.modalPresentationStyle=UIModalPresentationStyle.OverCurrentContext
self.presentViewController(viewController, animated: true, completion: nil)

For Swift 4 :

let viewController =  self.storyboard!.instantiateViewController(withIdentifier:  "XYZIdentifier") as! XYZViewController
viewController.providesPresentationContextTransitionStyle = true
viewController.definesPresentationContext = true
viewController.modalPresentationStyle = .overCurrentContext
self.present(viewController, animated: true, completion: nil)

And the backgroundcolor of your presented viewController should be clearColor.

If you want your modalVC to be over the tabbar you need to define the presentation style as UIModalPresentationOverFullScreen

[_presentedViewController setModalPresentationStyle:UIModalPresentationOverFullScreen];

[_presentingViewController presentViewController:_presentedViewController animated:YES completion:nil];

you can check the iOS7 example (see my comm) or you can simple try this:

remove this line from your "presenting" method

controller.view.backgroundColor = [UIColor clearColor];

now, in viewDidLoad of the ShareController add:

 self.view.backgroundColor = [UIColor clearColor];
 self.modalPresentationStyle = UIModalPresentationCurrentContext;
 self.modalPresentationStyle = UIModalPresentationFormSheet;

PS

if you have a navigationController... use

[self.navigationController presentViewController:controller animated:YES completion:nil];