Recently I encountered this code:-
self.view.layer.contents = (id)[UIImage imageNamed:#"img_bg.png"].CGImage;
This setup a background for the whole view of a UIViewController.
Usually, I would just set an UIImageView as subview, taking the whole area of the view from the UIViewController
Why would someone use one technique rather than an other ?
I found this one a bit disturbing because the background does not show in the storyboard; where I expect it.
that's a great question. Deeply, you are asking the different between View and Layer, you know we can think view as layer's delegate which can handle user's interaction with app or system. when there is no any interaction but render view, we can just use layer, that will take up less memory compared with the view。
Try this
self.view.backgroundColor = UIColor(patternImage: UIImage(named:"img_bg.png"))
Hope this will help
Cheers
You can try this:-
UIGraphicsBeginImageContext(self.view.frame.size)
UIImage(named: "img_bg.png")?.drawInRect(self.view.bounds)
let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
self.view.backgroundColor = UIColor(patternImage: image)
Hope this helps,
Thanks
Related
For some reason I am unable to add a UIImageView to my app. This is the code I am using and I have searched for quite a while to figure this out but haven't had any luck.
super.viewDidLoad()
let cloudimage = UIImage(named: "cloud")
let cloudView = UIImageView(image: cloudimage)
self.view.addSubview(cloudView)
cloudView.frame = CGRectMake(0,0,100,200)
The image is a .png in my assets folder so I don't think it's that. I do have auto layout settings enabled if that is an issue? I know it can be an issue with moving a UIImageView around by using its frame, but I think I should still be able to place the image in the View no problem with this code.
I am not quite sure what to do any suggestions would be great, this is extremely frustrating.
If your image is nil, your UIImageView will not render anything. Try debug your view hierarchy.
https://developer.apple.com/library/tvos/documentation/DeveloperTools/Conceptual/debugging_with_xcode/chapters/special_debugging_workflows.html
http://www.raywenderlich.com/98356/view-debugging-in-xcode-6
you need to add UIimageview to main view.
self.view.addSubview(cloudView)
Try by giving the image extension also while setting to UIImage
let cloudimage = UIImage(named: "cloud.png")
let cloudView = UIImageView(image: cloudimage)
cloudView.frame = CGRectMake(0,0,100,200)
self.view.addSubview(cloudView)
Checked and its working.
I have 2 imageViews like below. (ScrollView has subview of imageView)
i want to take the image of each one and merged to one.
i tried using taking screenshot and crop. but when it comes to different iphone screensizes and resolutions it doesn't work well.
can any one guide me how to do this?
Why not just add them both to one UIView?
It is also possible to add a subview to your image view and extend the frame.
[secondImageView setFrame:CGRectMake(x,y + newImageHeight,width,height)];
[self.myImageView setFrame:CGRectMake(x,y,width,height + newImageHeight)];
[self.myImageView addSubview:secondImageView];
I think your way is right, also you can solve scale size problem very easily with this method.
func mergeScreenshot() {
let layer = UIApplication.sharedApplication().keyWindow.layer
let scale = UIScreen.mainScreen().scale
UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale); // reconsider size property for your screenshot
layer.renderInContext(UIGraphicsGetCurrentContext())
let screenshot = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
UIImageWriteToSavedPhotosAlbum(screenshot, nil, nil, nil)
}
But you should edit sizes again. For example if you're using autolayout you can create IBOutlet and than use it instead of layer.frame.size property which I used.
Hope it helps.
I am not sure about how to present this question because I don't know the animation term that I should use.
I need to know about this tree presentation animation. As it is appearing form root to top.
Please take a look on attached .gif file and let me know if anyone know about this animation or if you can guide me with example.
I will really appreciate.
Thanks for your time.
The best option for you is to split up the gif into multiple images and then do the following:
NSArray *gifImagesArray = [NSArray arrayWithObjects:imageOne, imageTwo, imageThree, nil];
imageView.animationImages = animateImagesArray;
imageView.animationRepeatCount = 1;
imageView.animationDuration = 1.0f;
[imageView startAnimating];
Edit following comments:
If you can't use multiple images you have to write the animation yourself.
One suggestion is to add a circular mask to the UIImage and animate it's removal.
This link explains how to draw a circular CALayer: Circular Progress Bars in IOS
This one here will show you how to create a mask on a UIImage: Simply mask a UIView with a rectangle
now all you have to do is a simple animation.
I have a solution that will work for this problem.
We can use gif image and convert it into UIImage object. So image object will work same as animation.
Thanks all for your answers.
In my opinion, I will separate this animation to 4 parts:
animation to show full black tree from center.
animation to show Texts
animation to show blue leafs.
animation to show 2 buttons at bottom.
You can use this framework https://github.com/facebook/pop to operate all animations step by step or even Core Animation.
Please do more research... I think you will success to make one.
You can achieve this animation using simple UIImageView, that can load multiple images using animationImages property of UIImageView.
First, create one NSMutablerArray of images.
then asssign that images to imageView, and animationDuration for that images.
UIImageView *animationImageView = [[UIImageView alloc] initWithFrame:CGRectMake(60, 95, 86, 193)];
animationImageView.animationImages = images;
animationImageView.animationDuration = 0.5;
add the imageview to view.
[self.view addSubview:animationImageView];
[animationImageView startAnimating];
so what I currently wish to accomplish is for an image to be printed on the background of the IOS simulator screen, so inside of my viewDidLoad, I have this
var img = UIImage(named: "paper.jpg")
This can create the image variable, but I haven't found how to display it on the screen yet. It may seem like a trivial problem, but I haven't found any documentation on this online after searching for awhile. Thanks for reading.
Refer to the UIColor documentation.
In Swift, you have to call a convenience initializer. This is because in Swift, all Objective-C class methods which return an instance of their class become convenience initializers.
Here's how it looks in Swift:
self.view.backgroundColor = UIColor(patternImage: UIImage(named: "paper.jpg"))
+ (UIColor *)colorWithPatternImage:(UIImage *)image returns a UIColor instance, so it will become a convenience initializer in Swift. Similarly, UIImage imageNamed: becomes init(patternImage image: UIImage!).
since this is the marked answer, I felt the need to add a bit more code for completion.
as #senior has posted in his answer another way to add an image to your background is by the use of adding a UIImageView as a subview like so:
let img = UIImage(named: "paper.jpg")
let imgView = UIImageView(image: img)
self.view.addSubview(imgView)
You have to add your image to an ImageView and add this to the current view as a subview,
let img = UIImage(named: "paper.jpg")
let imgView = UIImageView(image: img)
self.view.addSubview(imgView)
iOS automatically flips the entire ViewController when using a RTL language like Arabic and does a great job with most of the layout, especially text. The default behavior is to flip the layout but leave UIImageViews the same orientation (since you generally don't want to reverse images).
Is there a way to specify that some images should be flipped (such as arrows) when the phone is set to a RTL language?
iOS 9 includes the imageFlippedForRightToLeftLayoutDirection method that you can use, that automatically flips the image in a UIImageView when in an RTL localization.
The best solution I found to date is marking the image in the assets file as mirror.
We can use imageFlippedForRightToLeftLayoutDirection which returns flipped image if current language is RTL(right to left). i.e
Objective-c
UIImage * flippedImage = [[UIImage imageNamed:#"imageName"] imageFlippedForRightToLeftLayoutDirection];
Swift 3
let flippedImage = UIImage(named: "imageName")?.imageFlippedForRightToLeftLayoutDirection()
Source: Apple Docs
You have to manually flip the UIImages in the UIImageViews you want when the phone is set to a RTL language. This can be easily achieved with this code:
UIImage* defaultImage = [UIImage imageNamed:#"default.png"];
UIImage* flipImage = [UIImage imageWithCGImage:sourceImage.CGImage scale:1.0 orientation: UIImageOrientationUpMirrored];
myImageview.image = flipImage;
I ended up using localized images for the forward and back arrows. This had the advantage of not having to add code each place the image was used and gives the opportunity to clean up the arrows if there are gradients that don't work well flipped.
While we wait for iOS 9 improved right to left support you could create a UIImageView subclass and override setImage to mirror inside the images as #nikos-m suggests and calling super.image = flipImage.
That way you can easily set all the images views you want to flip using custom classes in Interface Builder instead of having to add IBOutlets.
Swift 5
If you want to individualize the image flip, you can register each image with the direction you want since the layout direction is a trait:
let leftToRight = UITraitCollection(layoutDirection: .leftToRight)
let rightToLeft = UITraitCollection(layoutDirection: .rightToLeft)
let imageAsset = UIImageAsset()
let leftToRightImage = UIImage(named: "leftToRightImage")!
let rightToLeftImage = UIImage(named: "rightToLeftImage")!
imageAsset.register(leftToRightImage, with: leftToRight)
imageAsset.register(rightToLeftImage, with: rightToLeft)
This is the same as configuring it in the asset catalogue as #SergioM answered.