How to get a circle image in UIImageView - ios

I tried to get a circle image using layer, here is my code
_compassArrow.layer.cornerRadius = _compassArrow.frame.size.width / 2;
_compassArrow.layer.masksToBounds = YES;
_compassArrow.layer.borderColor = [UIColor whiteColor].CGColor
the compassArrow is an imageview which display the compass image. And when I run my program, it looks terrible:
my actual picture
I don't know what happened to it. I've add some constraints to it, to make it has equal width with the device. Does this influence my image?

I think you set cornerRadius before your constraints are applied. Try to put this code in layoutSubviews or viewDidLayoutSubviews for example.
This way, the _compassArrow.frame.size.width value will be the one after constraints applied on it, and you'll get the correct cornerRadius.

Here is a piece of code that should allow you to do this.
_compassArrow.layer.borderWidth = 1.0
_compassArrow.layer.masksToBounds = false
_compassArrow.layer.borderColor = UIColor.whiteColor().CGColor
_compassArrow.layer.cornerRadius = profilePicture.frame.size.width/2
_compassArrow.clipsToBounds = true

Related

Make UISwitch border width smaller

Hello I am trying to make UISwitch borderWidth smaller, but it doesn't look correct.
All I did is
layer.borderWidth = 0.5
instead of using storyboard try to customise switch programmatically . try using following code as if you change one parameter must adjust radius of switch too. Hope it helps
OnOffSwitch.layer.borderWidth = 1.0;
OnOffSwitch.layer.cornerRadius = 16.0;
OnOffSwitch.layer.borderWidth = 0.5;
OnOffSwitch.layer.cornerRadius = 17.0;

iOS: Image is not displaying properly in UIImageView

I have a UIImageView in which a UIImage is showing which comes from JSON. The problem is that I want to set the cornerRadius for the UIImageView. I put the following code for it:
imgVw.layer.cornerRadius = 30.0;
imgVw.layer.borderWidth = 2.0;
imgVw.layer.borderColor = [UIColor blackColor].CGColor;
It displays the cornerRadius and border for UIImageView but not in the proper way. The image is showing outside the corners like in screenshot.
You need to set the masksToBounds property of layer to YES like this
self.imgVw.layer.masksToBounds = YES;
Set the clipsToBounds property of UIImageView to YES.
Like
set imgVw.clipsToBounds=YES;

Access the UIImageView of the background image of a UIButton

I have a UIButton, and I would like to access the UIImageView of its background image so that I can make the image circular. I know that I can affect the image itself but I would prefer to do this more elegantly. I also know that I can use the button.currentBackgroundImage property to get the UIImage in the background, but I want the view itself. Once I have the view I intend to use this code:
buttonImageView.layer.cornerRadius = buttonImageView.frame.size.width / 2;
buttonImageView.clipsToBounds = YES;
How can I access the buttonImageView?
EDIT:
Due to #vhristoskov's suggestions, I tried cropping the button itself with this code:
self.button.layer.cornerRadius = self.button.frame.size.width/2;
self.button.clipsToBounds = YES;
And it made this shape:
After debugging I found that frame.size.width was 46, when it should have been 100. So I tried this code instead:
self.button.layer.cornerRadius = self.button.currentBackgroundImage.size.width/2;
self.button.clipsToBounds = YES;
And that produced this shape:
And this time, the cornerRadius was being set to 65. So it actually seems like my problem is that I don't have the correct width at the moment. Which property should I access to get the correct number?
Well as I guessed and as you've already found - the problem is in the button size. To be sure that your button's size at runtime is what you expected to be - review your constraints. In the example below the button has vertical and horizontal central alignment and fixed width and height.
Constraints:
To have perfectly circular button you should have button.width == button.height. If this condition is met your code should work like a charm:
self.button.layer.cornerRadius = CGRectGetWidth(self.button.frame) / 2;
self.button.clipsToBounds = YES;
Assuming that you called something like:
[self.myButton setBackgroundImage:[UIImage imageNamed:#"image"] forState:UIControlStateNormal];
in viewDidLoad or earlier, you can then call the following in viewDidAppear:
if (self.myButton.subviews.count > 0 && [self.myButton.subviews[0] isKindOfClass:[UIImageView class]]) {
UIImageView *imageView = self.myButton.subviews[0];
imageView.layer.cornerRadius = imageView.frame.size.width / 2;
imageView.clipsToBounds = YES;
}
but it is not more elegant as the subview ordering is an implementation detail of UIButton and may change at any time.

How to Clone A UIImageView

I have a UIImageView and I want to make a copy of it and place it somewhere on the screen. How do I do this?
I currently only know how to copy and paste the image manually and make a separate IBOutlet for each one, but this is very inefficient because I want to make a game that generates obstacles (UIImageViews) forever so I can't do it the manual way.
You want to make sure you match all of the properties up as well, like size, clipping, image aspect, opacity, etc.
CGPoint locationOfCloneImageView = CGPointMake(0, 0);//x and y coordinates of where you want your image. (More specifically, the x and y coordinated of where you want the CENTER of your image to be)
UIImageView *cloneImageView = [[UIImageView alloc] initWithImage:originalImageView.image];
cloneImageView.frame = CGRectMake(0, 0, originalImageView.frame.size.width, originalImageView.frame.size.height);//same size as old image view
cloneImageView.alpha = originalImageView.alpha;//same view opacity
cloneImageView.layer.opacity = originalImageView.layer.opacity;//same layer opacity
cloneImageView.clipsToBounds = originalImageView.clipsToBounds;//same clipping settings
cloneImageView.backgroundColor = originalImageView.backgroundColor;//same BG color
cloneImageView.tintColor = originalImageView.tintColor;//matches tint color.
cloneImageView.contentMode = originalImageView.contentMode;//matches up things like aspectFill and stuff.
cloneImageView.highlighted = originalImageView.highlighted;//matches whether it's highlighted or not
cloneImageView.opaque = originalImageView.opaque;//matches can-be-opaque BOOL
cloneImageView.userInteractionEnabled = originalImageView.userInteractionEnabled;//touches are detected or not
cloneImageView.multipleTouchEnabled = originalImageView.multipleTouchEnabled;//multi-touches are detected or not
cloneImageView.autoresizesSubviews = originalImageView.autoresizesSubviews;//matches whether or not subviews resize upon bounds change of image view.
//cloneImageView.hidden = originalImageView.hidden;//commented out because you probably never need this one haha... But if the first one is hidden, so is this clone (if uncommented)
cloneImageView.layer.zPosition = originalImageView.layer.zPosition+1;//places it above other views in the parent view and above the original image. You can also just use `insertSubview: aboveSubview:` in code below to achieve this.
[originalImageView.superview addSubview:cloneImageView];//adds this image view to the same parent view that the other image view is in.
cloneImageView.center = locationOfCloneImageView;//set at start of code.
You will need to create one new UIImageView with its new frame where you want to place it. set its image property of your existing imageView's image, and after that add it to your view.
UIImageView *newImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,50,50)];
newImageView.image = oldImageView.image;
[self.view addSubView:newImageView]

How to shrink UIImageview contents with better interpolation

I'm shrinking a UIImageView but it's looks horrible and aliased.
I've tried changing the 'minifactionFilter' property but I don't see any effects.
Is there a special way to implement this? There's not much info in apple's docs.
self.imageView.layer.minificationFilter = kCAFilterLinear;
self.imageView.layer.cornerRadius = 9.0;
self.imageView.layer.masksToBounds = YES;
I know the layer properties are working as I can see the round corners but interpolation always looks the same.
kCAFilterNearest
kCAFilterLinear
kCAFilterTriLinear

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