How to show a view with semi transparency from IOS application controller

Question

Say I am having ten view controllers in my IOS application. Suppose specific events (eg: BLE connectivity success/failure) will be getting intimated in application controller.
I want to block the current view controller (whichever view controller it may be) and show a view with semi transparency for 2 seconds based on the event from application controller.

How can I achieve this in IOS. Any help may be highly appreciated.

score 1 · Answer 1 · answered Mar 31 '15 at 12:30

1

Just set your view alpha property like

viewController.view.alpha = 0.5;

answered Mar 31 '15 at 12:30

Retro

3,985
2
17
41

Shall I push view controller from application controller? or should I check which ever the view controller is present, I should add this view on top of that? – Sreehari Mar 31 '15 at 12:35
Just present view as Model View! – Retro Mar 31 '15 at 12:38

score 1 · Accepted Answer · edited Mar 31 '15 at 12:41

My solution for the above problem is this:

Create a custom transparent overlay UIView that comes over any view, navigationbar and tabbbar.

-In the navigation controller (or tabbar controller) that your view controller is embedded in I create a custom view with it's frame equal to the frame of the navigation controller's view.

-Then I set it offscreen by setting it's origin.y to navigationController.view.height

-Then I create 2 functions -(void)showOverlay and -(void)hideOverlay that animate the overlay view on and off screen:

- (void)hideOverlay{
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.3];

    CGRect frm = self.helpView.frame;//helpView is my overlay
    frm.origin.y = self.offscreenOffset; //this is an Y offscreen usually self.view.height
    self.helpView.frame = frm;

    [UIView commitAnimations];
}

- (void)showOverlay{

    [self.view bringSubviewToFront:self.helpView];

    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.3];

    CGRect frm = self.helpView.frame;
    frm.origin.y = self.onscreenOffset;
    self.helpView.frame = frm;

    [UIView commitAnimations];
}

-In my view controller I can just call

[(MyCustomNavCtrl *)self.navigationController showOverlay];
[(MyCustomNavCtrl *)self.navigationController hideOverlay];
And that's about it.

score 0 · Answer 3 · answered Mar 31 '15 at 12:33

0

setting your alpha level of a view will make all the subviews transparent as well. if you just want your background to be semi transparent do the following.

myView.backgroundColor = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 0.5)

(Swift Syntax)

answered Mar 31 '15 at 12:33

Matt Bolt

332
1
2
9

How to show a view with semi transparency from IOS application controller

3 Answers3