I'm making a weather app and for showing maximum and minimum temperature of the day, I'm using a UIView that's corners I've rounded by using .layer.cornerRadius. Now I want to add a gradient layer with different colors (symbolizing temperature), but the gradientLayer doesn't appear. Here's my viewDidLoad(), the views name is currentMinMaxTemperatureView:
let gradientLayer = CAGradientLayer()
gradientLayer.frame = currentMinMaxTemperatureView.bounds
gradientLayer.cornerRadius = currentMinMaxTemperatureView.cornerRadius
gradientLayer.colors = [UIColor.blue, UIColor.yellow, UIColor.red]
currentMinMaxTemperatureView.layer.addSublayer(gradientLayer)
Why doesn't it appear? When running this, my view looks like this:
There are a couple of problems with your code:
First, as #archLucifer mentioned, CAGradientLayer expects CGColor, not UIColor.
Simply convert your colours like so:
[UIColor.blue.cgColor, UIColor.yellow.cgColor, UIColor.red.cgColor]
Second, you want to make sure you add your gradient after your currentMinMaxTemperatureView is added to the superview. Otherwise, its bounds will be nil.
Try adding the gradient later in your UIViewController lifecycle, like ViewDidLayoutSubviews()
Try the following
gradientLayer.colors = [UIColor.blue.cgColour, UIColor.yellow.cgColour, UIColor.red.cgColour]
Related
As people already know that this seems simple but Stackoverflow has no answers for me. Basically I want to make an image darker like the bg image of Beijing ancient building below:
to make it darker so that the tags on it can be more contrasting obvious.
I tried adding a layer which is one of the answers from Stackoverflow or adding tintColor but none of them worked, is there any method that can really work? Thank you, guys.
I'm under iOS 13 and swift 5.1
Add this UIView extension to your project
extension UIView {
func addoverlay(color: UIColor = .black,alpha : CGFloat = 0.6) {
let overlay = UIView()
overlay.autoresizingMask = [.flexibleWidth, .flexibleHeight]
overlay.frame = bounds
overlay.backgroundColor = color
overlay.alpha = alpha
addSubview(overlay)
}
//This function will add a layer on any `UIView` to make that `UIView` look darkened
}
then use it like on any UIView(In your Case yourImageView)
yourImageView.addoverlay()
Or you can specify your own overlay color and alpha value
yourImageView.addoverlay(color: .blue, alpha: 0.5)
This question already has answers here:
How to Apply Gradient to background view of iOS Swift App
(30 answers)
Closed 4 years ago.
For example, the left side of the label is gray and the right side is blue. I want the color to be gray on the left side, but become darker as it goes right until the right side of the label is completely blue. Is there a way to do this without looking for an image online and setting the background color of the label to be the image?
You can add UILabel into the UIView and add Gradient Layer to that UIView.
For add Gradient Layer you can use following code.
let view = UIView(frame: CGRect(x: 0, y: 0, width: 320, height: 50))
let gradient = CAGradientLayer()
gradient.frame = view.bounds
gradient.colors = [UIColor.white.cgColor, UIColor.black.cgColor]
view.layer.insertSublayer(gradient, at: 0)
You can also refer this question
Apple provides this live blurring view class UIVisualEffectView and you use it with a UIBlurEffect which takes one of three available UIBlurEffectStyles:
enum UIBlurEffectStyle : Int {
case ExtraLight
case Light
case Dark
}
Now for demo purposes I set up two effect views with the styles Light and ExtraLight:
let lightBlur = UIBlurEffect(style: UIBlurEffectStyle.Light)
let extraLightBlur = UIBlurEffect(style: UIBlurEffectStyle.ExtraLight)
let lightView = UIVisualEffectView(effect: lightBlur)
lightView.frame = CGRectMake(10, 30, 150, 150)
self.view.addSubview(lightView)
let extraLightView = UIVisualEffectView(effect: extraLightBlur)
extraLightView.frame = CGRectMake(160, 30, 150, 150)
self.view.addSubview(extraLightView)
So far so good, everything works as expected, they blur images:
and kind of work on colors, too:
but when it comes to a white background this happens:
The Light effect on the left works as expected, but the ExtraLight effect on the right leaves some kind of gray square behind.
Now the question: Is there any kind of trick or method that would enable me to use an extra light blur effect on white background (with live blurring support) AND remove that ugly gray shadow?
As far as I know the additional tint is a built-in feature of the UIVisualEffectView class. If you examine the view hierarchy with Xcode, you can see that there are two default subviews in the visual effect view instance: UIVisualEffectBackdropView and UIVisualEffectSubview. (I assume that these are private classes.) If you inspect UIVisualEffectSubview you can see that it has a background color which causes the unwanted tint that you've noticed.
I am not sure if there's an officially supported way to remove it, but you can modify this background color by filtering to the name of the private subview:
if let vfxSubView = visualEffectView.subviews.first(where: {
String(describing: type(of: $0)) == "_UIVisualEffectSubview"
}) {
vfxSubView.backgroundColor = UIColor.white.withAlphaComponent(0.7)
}
(Swift 5 compatible)
The default tint is around 70% opacity, so the easiest is to use the target background color with 0.7 alpha component.
I've also noticed that this might reset to the default value if the visual effect contains a custom subview. If I add this same snippet to the viewDidLayoutSubviews function of the view's controller, then it will keep the custom background color even after the built-in subview is updated.
Here's an example with a dark blur effect style. The top part shows the default tint and the bottom version has a custom black background color with 70% opacity.
If you just want the blur and your blurred view is gonna be stationary, you could use the UIImageEffects class and change the tintColor to a "full" white:
- (UIImage *)applyExtraLightEffect
{
UIColor *tintColor = [UIColor colorWithWhite:0.97 alpha:0.82];
return [self applyBlurWithRadius:20 tintColor:tintColor saturationDeltaFactor:1.8 maskImage:nil];
}
As far as I know you can't change it in the UIVisualEffectView.
You can try :
var visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .Light))
visualEffectView.frame = imageView.bounds
imageView.addSubview(visualEffectView)
Simple Solution
I could find a simple solution inspired by Shannon Hughes' Blog Post. Just add a white background color with transparency to the effect view. I don't know if it is exactly like extraLight but for me it is close enough.
let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .light))
visualEffectView.frame = sectionHeaderView.bounds
visualEffectView.backgroundColor = UIColor(white: 1.0, alpha: 0.9)
sectionHeaderView.addSubview(visualEffectView)
The following code should do the trick to give it a the desired tint:
let visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .regular))
visualEffectView.subviews.forEach { subview in
subview.backgroundColor = UIColor.blue.withAlphaComponent(0.2)
}
Important Note:
I wouldn't recommend adding a check for "_UIVisualEffectSubview" since this class can change on subsequent iOS updates.
Also, there is a possibility of app getting rejected because of this.
iOS 15 has the nice
.background(.ultraThinMaterial)
but it still suffers from the nasty grey tint. Wish there was an option to blur background views without any tint.
I tried a simple color-correct hack which worked for my background color but only in light mode! For dark mode I just made the background solid black (no translucent blur)
.background(
// negate the slight grey tint of ultrathinmaterial
Color("materialTintColorCorrect")
.background(.ultraThinMaterial)
)
My "materialTintColorCorrect" color asset was #F0F8FF 27% opacity for light mode and #000000 100% opacity for dark.
let vc = UIViewController()
vc.view.frame = self.view!.frame
let efv = UIVisualEffectView(effect: UIBlurEffect(style: UIBlurEffectStyle.light))
efv.frame = vc.view.frame
vc.view.addSubview(efv)
self.addChildViewController(vc)
self.view.addSubview(vc.view)
// below method has a bug
// self.present(vc, animated: true, completion:nil)
I would recommend adding your extraLightView to a view of UIColor(white: 1.0, alpha: 0.x), where x can be modified based on the scroll view's contentOffset. When there's nothing behind the view, your extraLightView will be white when x is 1. When you scroll and modify x, you won't be modifying the UIVisualEffectView (which is highly discouraged), but rather its parent view, which is perfectly safe.
Works with Swift 5
My way of making the visual effect view completely white when the background view is white.
let blurView = UIVisualEffectView(effect: UIBlurEffect(style: .light))
blurView.backgroundColor = UIColor.white.withAlphaComponent(0.7)
I want to set a Dotted / Dashed border for my UITextField and UITextView.
How can I do that? I know that, I can set border with this line of code:
[self.textFieldCardTitle.layer setBorderWidth:1.0];
[self.textFieldCardTitle.layer setBorderColor:[[UIColor whiteColor] CGColor]];
Notice: I already have the idea to add a UIImageView behind the UITextView and set there an image with dashed border. But I don't want to solve it that way.
You could try, for example, next approach:
1) Create image that will represent your border (for example: one dot and space)
2) Add image to project.
3) Set border (as in code in your question) and set color with pattern:
[self.textFieldCardTitle.layer setBorderWidth:6.0];
[self.textFieldCardTitle.layer setBorderColor:[[UIColor colorWithPatternImage:[UIImage imageNamed:#"dashed_white.png"]] CGColor]];
As border is drawn along 4 sides (left, right, bottom, top) you should use square image: for example, pixel in middle is black and pixels around it are transparent. So copies of that image will be placed around the view.
Just use following code for Dotted / Dashed Border around UIView or UITextField or any other view:-
CAShapeLayer * _border = [CAShapeLayer layer];
_border.strokeColor = [UIColor redColor].CGColor;
_border.fillColor = nil;
_border.lineDashPattern = #[#4, #2];
[YOURVIEW.layer addSublayer:_border];
//for a square effect
_border.path = [UIBezierPath bezierPathWithRect:YOURVIEW.bounds].CGPath;
//for a rounded effect
//_border.path = [UIBezierPath bezierPathWithRoundedRect:YOURVIEW.bounds cornerRadius:txtUserName.frame.size.height / 2].CGPath;
_border.frame = YOURVIEW.bounds;
For more details, Refer this Answer.
Hope, this is what you're looking for. Any concern get back to me. :)
Here's what I did with Swift:
self.textFieldCardTitle.layer.borderWidth = 3
self.textFieldCardTitle.layer.borderColor = (UIColor(patternImage: UIImage(named: "dot")!)).CGColor
Free bonus, I attached the pics below. Unless StackOverflow changes its background, you probably won't see them as they are white squares on a white background, so you'll find the urls below as well.
http://i.stack.imgur.com/X7PfM.png -> rename it to dot.png
http://i.stack.imgur.com/IemhF.png -> rename it to dot#2x.png
http://i.stack.imgur.com/CSjZT.png -> rename it to dot#3x.png
Swift 5, for #Meet Doshi's answer
class CustomTextField: UITextField{
let dashBorder = CAShapeLayer()
override init(frame: CGRect) {
super.init(frame: .zero)
dashBorder.strokeColor = UIColor.lightGray.cgColor
dashBorder.fillColor = nil
dashBorder.lineDashPattern = [4, 2]
layer.addSublayer(dashBorder)
}
override func layoutSubviews() {
super.layoutSubviews()
dashBorder.path = UIBezierPath(roundedRect: bounds, cornerRadius: 5).cgPath
dashBorder.frame = bounds
}
}
I've seen similar questions, but haven't found workable answers.
I want to mask a UIView using a grey image (need to convert to alpha scale for masking). The UIView has background. It should be easy to mask an image, but I want to mask any UIView.
Any clues will be appreciated.
I've been working on this problem for a couple of hours and have a solution that I think will do what you want. First, create your masking image using whatever means you see fit. Note that we only need the alpha values here, all other colours will be ignored, so make certain that the method you use supports alpha values. In this example I'm loading from a .png file, but don't try it with .jpg files as they don't have alpha values.
Next, create a new layer, assign your mask to its contents and set this new layer to your UIView's own layer, like so: you should find that this masks the UIView and all its attached subviews:
UIImage *_maskingImage = [UIImage imageNamed:#"mask"];
CALayer *_maskingLayer = [CALayer layer];
_maskingLayer.frame = theView.bounds;
[_maskingLayer setContents:(id)[_maskingImage CGImage]];
[theView.layer setMask:_maskingLayer];
With this done, you can set the UIView's background colour to whatever you like and the mask will be used to create a coloured filter.
EDIT: As of iOS8 you can now mask a view simply by assigning another view to its maskView property. The general rules stay the same in that the maskView's alpha layer is used to determine the opacity of the view it is applied to.
For apps targeting iOS 8.0+ this worked well (in this case, using a gradient as the mask) It avoids any need to resize or position the mask.
// Add gradient mask to view
func addGradientMask(targetView: UIView)
{
let gradientMask = CAGradientLayer()
gradientMask.frame = targetView.bounds
gradientMask.colors = [UIColor.blackColor().CGColor, UIColor.clearColor().CGColor]
gradientMask.locations = [0.8, 1.0]
let maskView: UIView = UIView()
maskView.layer.addSublayer(gradientMask)
targetView.maskView = maskView
}
In my case, I want to remove the mask once the user starts scrolling. This is done with:
func scrollViewWillBeginDragging(scrollView: UIScrollView) {
exerDetailsTableView.maskView = nil
}
where the view is defined as an #IBOutlet:
#IBOutlet weak var exerDetailsTableView: UITableView!
Result:
I don't know the exact code off the top of my head but the basic idea is to have two UIViews. One UIView would have it's image property set to be the grey scale image and the other UIView would be set as usual the only difference is that you would position the initial UIView directly on top of the UIView containing the "normal" image.
I hope that is enough to push your idea a step further.