I see this topic in quite a few places but I can't figure out why exactly my code doesn't work.
I have an image of an artificial horizon that goes from -90 to 90 degrees. I want to view it through a small window which just shows around -20 to 20 degrees. Then I want to move the image up and down based on the angle my robot is leaning.
I started by adding a UIImage to a UIImageView. All of the alignment is correct. Then I thought the easiest way to move the image up and down was to add the UIImageView to a UIScrollView. Now I can't figure out how to get the alignment right. I see the image in there if I drag in the scrollview but as soon as I let go it goes back to where it was.
Here is the code I have. This is the first Swift code I have written so if there is a better way to do this I welcome any ridicule (just kidding, be gentle)
override func viewDidLoad() {
super.viewDidLoad()
let imageRect = CGRectMake(self.view.frame.width / 2 - 100, self.view.frame.height / 2, 200, 200)
self.myImageView = UIImageView.init()
self.myImageView = UIImageView(frame: imageRect)
self.myImageView.contentMode = UIViewContentMode.Center
self.myImageView.clipsToBounds = true
self.myImageView.image = UIImage.init(named:"horizon")
//self.view.addSubview(self.image)
self.myScrollView = UIScrollView(frame: imageRect)
self.myScrollView.contentSize = CGSize(width: imageRect.width, height: imageRect.height)
self.myImageView.center = self.myScrollView.center
self.myScrollView.frame = imageRect
self.myScrollView.backgroundColor = UIColor.blackColor()
self.myScrollView.contentOffset = CGPoint(x: 0, y: 0)
self.myScrollView.addSubview(self.myImageView)
self.view.addSubview(self.myScrollView)
/////////
self.connectionStatusLabel.text = "Disconnected"
self.connectionStatusLabel.textColor = UIColor.redColor()
self.textBox.font = UIFont(name: self.textBox.font!.fontName, size: 8)
// Watch Bluetooth connection
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ViewController.connectionChanged(_:)), name: BLEServiceChangedStatusNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ViewController.dataReceived(_:)), name: BLEDataChangedStatusNotification, object: nil)
// Start the Bluetooth discovery process
btDiscoverySharedInstance
}
You have to set the scrollView's contentSize to the actual image size not the imageView's size. And set the imageView's size to the actual image size as well:
let image = UIImage.init(named:"horizon")
// Set the imageView's size to the actual image size
self.myImageView.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
...
...
// Set the scrollView's contentSize to the actual image size
self.myScrollView.contentSize = image.size
Related
I have an UITextField component which has an icon on the right side of it. Icon is just an UIImageView. I'm trying to give inset to UIImageView with below code
imageView.image = UIImage(named: "example")?.withAlignmentRectInsets(UIEdgeInsets(top: -4, left: 0, bottom: -4, right: 0))
However, It doesn't work cuz It's frame hasn't been set when setting Its' Image. I'm giving Its frame with below code;
iconImageView.frame = CGRect(
x: bounds.size.width - iconWidth - iconMarginLeft,
y: bounds.size.height - textHeight() - iconMarginBottom,
width: iconWidth,
height: textHeight()
)
and how I setup UIImageView
fileprivate func createIconImageView() {
let iconImageView = UIImageView()
iconImageView.backgroundColor = .clear
iconImageView.contentMode = .scaleAspectFill
iconImageView.autoresizingMask = [.flexibleTopMargin, .flexibleRightMargin]
if (hasToolTip) {
let tapGesture = UITapGestureRecognizer(target: self, action:#selector(toolTipTapped(_:)))
iconImageView.addGestureRecognizer(tapGesture)
iconImageView.isUserInteractionEnabled = true
let image = UIImage(named: "infotooltip")
image?.accessibilityIdentifier = "tooltipImage"
iconImageView.image = image!
changeIconAlphaToOne()
self.iconImageView = iconImageView
} else {
self.iconImageView = iconImageView
changeIconAlphaToZero()
}
addSubview(iconImageView)
}
My problem is that, I need to give UIEdgeInset to the image. However, because I'm trying to give it before setting the frame, It doesn't work. How can I achieve this?
I also try to resize the image by referencing below post but doesn't work for me. I also DO NOT want to put it inside a content view which will make my component class more complicated.
The simplest way to resize an UIImage?
I am struggling for 2 hours now to get a UIScrollView.contentSize with the size of a UIImage, but the UIImage doesn't return a proper size, I have no idea why.
The result is that my scrollView content is square(the same as the scrollView's frame) and I can't scroll to the side of the image.
This is really frustrating! You can see in the debugger that my image1.size is invalid.
you are accessing an image from array which doesn't exist see your console log it's clearly saying index out of range. that's why your not getting any size and height as well because there's no image in the specific index
Your image view size is showing wrong because your scrollview content size is wrong. Use this method than print your image view frame. It will work
override func viewDidLayoutSubviews()
{
self.scrollView1.delegate = self
self.scrollView1.contentSize = CGSize(width:self.view.frame.size.width, height: self.view.frame.size.height)
}
OK, I have been struggling with this for a while now, and finally I was able to find the answer. The problem was indeed in the content size, and I was finally able to calculate it correctly as below:
let tempScrollView = UIScrollView(frame: self.imageLocationsArray[imageID])
let tempImageView = UIImageView(image: image)
//determine proportions of image against frame
let imageWidthFactor = image.size.width / tempScrollView.frame.width
let imageHeightFactor = image.size.height / tempScrollView.frame.height
//image is too wide
if imageWidthFactor > imageHeightFactor {
tempImageView.frame = CGRect(x: 0, y: 0, width: tempScrollView.frame.width * imageWidthFactor / imageHeightFactor, height: tempScrollView.frame.height)
}
//image is too tall
else {
tempImageView.frame = CGRect(x: 0, y: 0, width: tempScrollView.frame.width, height: tempScrollView.frame.height * imageHeightFactor / imageWidthFactor)
}
My background image is set with UIView extension.
extension UIView {
func addBackground() {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: "index_clear")
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}}
For segue animation the view moves from left to right. The background image is way larger than the screen, what is visible while the animation.
How can I cut the background image to perfectly fit into the view?
.ScaleAspectFit does the job, but since it's a picture it looks bad.
Help is very appreciated.
You can use .ScaleAspectFill to crop the image rather than scale it to fit. This won't distort your image, but obviously you won't be able to see the whole thing.
You need to ensure that you set clipsToBounds=true on the UIImageView so that the cropped area isn't visible
extension UIView {
func addBackground() {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: "index_clear")
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
imageViewBackground.clipsToBounds=true
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}
I can set an image to my TableView background, but the image is in the center of the view.
How can I set the image to top ?
I'm using staticTableView
let image = UIImageView(image: UIImage(named: "img.jpg"))
self.settingsTableView.backgroundView = image
self.settingsTableView.backgroundView?.frame = CGRectZero
self.settingsTableView.backgroundView?.contentMode = UIViewContentMode.ScaleAspectFit
If you're using a static table and theres no chance of changing it you might want to take an approach like this:
override func viewDidLoad() {
super.viewDidLoad()
//Create the UIImage
let image = UIImage(named: "testing")
//Create a container view that will take all of the tableView space and contain the imageView on top
let containerView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: self.view.bounds.width, height: self.view.bounds.height))
//Create the UIImageView that will be on top of our table
let imageView = UIImageView(frame: CGRect(x: 0.0, y: 0.0, width: self.view.bounds.width, height: image!.size.height))
//Set the image
imageView.image = image
//Clips to bounds so the image doesnt go over the image size
imageView.clipsToBounds = true
//Scale aspect fill so the image doesn't break the aspect ratio to fill in the header (it will zoom)
imageView.contentMode = UIViewContentMode.ScaleAspectFit
containerView.addSubview(imageView)
self.tableView.backgroundView = containerView
}
Make the cells or the headers transparent as you wish. I don't know how your UI should work. This method WON'T scroll the imageView but you can simply do it in the scrollView delegate method. Let me know if you need it to scroll and I'll help you out
I want to put images in UIScrollView. However, the problem is that when I try to put an image larger than UIScrollView, UIScrollView shows the upper part of images. I would like the scrollview to show the bottom part of the image. Right now, I have the following code:
let imgBot1 = UIImage(named:"Img1.jpg");
let imgBot2 = UIImage(named:"Img4.jpg");
let imgBot3 = UIImage(named:"Img5.jpg");
//Adding UIImage in UIImageView
let imgView1 = UIImageView(image:imgBot1)
let imgView2 = UIImageView(image:imgBot2)
let imgView3 = UIImageView(image:imgBot3)
//creating UIScrollView
let scrView2 = UIScrollView()
scrView2.frame = CGRectMake(0, self.view.frame.height/2,
self.view.frame.width, self.view.frame.height)
//content size of the scrollview
scrView2.contentSize = CGSizeMake(self.view.frame.width*3, self.view.frame.height)
//Size and place of UIImageView
imgView1.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height)
imgView2.frame = CGRectMake(width, 0, self.view.frame.width, self.view.frame.height)
imgView3.frame = CGRectMake(width*2, 0, self.view.frame.width, self.view.frame.height)
//adding the scrollview to the view
self.view.addSubview(scrView2)
scrView2.addSubview(imgView1)
scrView2.addSubview(imgView2)
scrView2.addSubview(imgView3)
scrView2.pagingEnabled = true
//Initial location of the scrollview
scrView2.contentOffset = CGPointMake(0, 0);
I would like to know how I can make the scrollview to show the bottom part of the image, and not the top part. Will you help me out?
I made this code, hope it will work for you. I used the storyboard, made a scrollView, added an imageView and added constrains to the image view to stick to the edges (don't know it that's necessary).
imageView = UIImage(named: "image")
scrollView.contentOffset = CGPoint(x: 0, y: image.image!.size.height)