iOS White to Transparent Gradient Layer is Gray
clearColor has a black color channel with an alpha of 0, so I had to use [UIColor colorWithWhite:1 alpha:0] and it works fine.
uiview
Swift addsubview and remove it
Thanks for help. This is the solution: I created the subview and i add a gesture to remove it @IBAction func infoView(sender: UIButton) { var testView: UIView = UIView(frame: CGRectMake(0, 0, 320, 568)) testView.backgroundColor = UIColor.blueColor() testView.alpha = 0.5 testView.tag = 100 testView.userInteractionEnabled = true self.view.addSubview(testView) let aSelector : Selector = “removeSubview” let tapGesture = … Read more
Swift UIView background color opacity
You can set background color of view to the UIColor with alpha, and not affect view.alpha: view.backgroundColor = UIColor(white: 1, alpha: 0.5) or view.backgroundColor = UIColor.red.withAlphaComponent(0.5)
Getting reference to the top-most view/window in iOS application
Whenever I want to display some overlay on top of everything else, I just add it on top of the Application Window directly: [[[UIApplication sharedApplication] keyWindow] addSubview:someView]
Check if a subview is in a view
You are probably looking for UIView’s -(BOOL)isDescendantOfView:(UIView *)view; taken in UIView class reference. Return Value YES if the receiver is an immediate or distant subview of view or if view is the receiver itself; otherwise NO. You will end up with a code like : Objective-C – (IBAction)showPopup:(id)sender { if(![self.myView isDescendantOfView:self.view]) { [self.view addSubview:self.myView]; } … Read more
How to create a UIView bounce animation?
A simpler alternative to UIDynamicAnimator in iOS 7 is Spring Animation (a new and powerful UIView block animation), which can give you nice bouncing effect with damping and velocity: Objective C [UIView animateWithDuration:duration delay:delay usingSpringWithDamping:damping initialSpringVelocity:velocity options:options animations:^{ //Animations } completion:^(BOOL finished) { //Completion Block }]; Swift UIView.animateWithDuration(duration, delay: delay, usingSpringWithDamping: damping, initialSpringVelocity: velocity, options: … Read more
Interaction beyond bounds of UIView
Yes. You can override the hitTest:withEvent: method to return a view for a larger set of points than that view contains. See the UIView Class Reference. Edit: Example: – (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event { CGFloat radius = 100.0; CGRect frame = CGRectMake(-radius, -radius, self.frame.size.width + radius, self.frame.size.height + radius); if (CGRectContainsPoint(frame, point)) { return self; … Read more
Correct way to load a Nib for a UIView subclass
MyViewClass *myViewObject = [[[NSBundle mainBundle] loadNibNamed:@”MyViewClassNib” owner:self options:nil] objectAtIndex:0] I’m using this to initialise the reusable custom views I have. Note that you can use “firstObject” at the end there, it’s a little cleaner. “firstObject” is a handy method for NSArray and NSMutableArray. Here’s a typical example, of loading a xib to use as a … Read more
Avoid animation of UICollectionView after reloadItemsAtIndexPaths
It’s worth noting that if you’re targeting iOS 7 and above, you can use the new UIView method performWithoutAnimation:. I suspect that under the hood this is doing much the same as the other answers here (temporarily disabling UIView animations / Core Animation actions), but the syntax is nice and clean. So for this question … Read more
What is the relationship between UIView’s setNeedsLayout, layoutIfNeeded and layoutSubviews?
I’m still trying to figure this out myself, so take this with some skepticism and forgive me if it contains errors. setNeedsLayout is an easy one: it just sets a flag somewhere in the UIView that marks it as needing layout. That will force layoutSubviews to be called on the view before the next redraw … Read more