Setting alpha on UIView sets the alpha on its subviews which should not happen

Question

According to the documentation for UIVIew @property(nonatomic) CGFloat alpha

The value of this property is a floating-point number in the

Answer 1

Simplest solution as discussed is to change the alpha as follows : Updated version for Xcode 8 Swift 3 is :

yourParentView.backgroundColor = UIColor.black.withAlphaComponent(0.4)

Objective C:

yourParentView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.5];

Refer Apple Developer Docs here : https://developer.apple.com/reference/uikit/uiview/1622417-alpha

Answer 2

Here is a bit complex solution:

UIView *container;
UIView *myView;
UIView *anotherView;

myView.alpha = 0.5;
[container addSubview:myView];

anotherView.alpha = 1;
[container addSubview:anotherView];

Use a container view as superview, anotherView and myView are both subview in container, anotherView is not a subview in myView.

Answer 3

In swift

view.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.5)

UPDATED FOR SWIFT 3

view.backgroundColor = UIColor.white.withAlphaComponent(0.5)

Answer 4

Don't set the alpha directly on the parent view. Instead of it use the below line of code which will apply transparency to parentview without affecting its child views.

[parentView setBackgroundColor:[[UIColor clearColor] colorWithAlphaComponent:0.5]];