uiimageview not showing image in view controller - xcode

I am trying to display a chart image in my view controller. I have an image called 'powerchart' in my assets, but I cannot get it to display in the view controller. I am trying to build the app programatically, therefore not using storyboard. code below. I've tried using several combinations of UIImage. functions, but cannot get the image to load. Any help would be appreciated
import Foundation
import UIKit
class MarketViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.yellow
navigationController?.title = "Market"
view.addSubview(marketChart)
setupMarketScreen()
}
// create chart
let marketChart: UIImageView = {
let chart = UIImageView()
chart.image = UIImage.init(imageLiteralResourceName: "powerchart")
return chart
}()
func setupMarketScreen() {
marketChart.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive=true
marketChart.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive=true
marketChart.widthAnchor.constraint(equalToConstant: 500).isActive=true
marketChart.heightAnchor.constraint(equalToConstant: 200).isActive=true
}
}

Declare This Way. Below code works fine for me.
import UIKit
class ViewController: UIViewController {
/*
let marketChart: UIImageView = {
let chart = UIImageView()
chart.image = UIImage.init(imageLiteralResourceName: "backimg3.jpeg")
return chart
}() */
let marketChart:UIImageView = UIImageView.init(image: UIImage (named: "backimg3.jpeg"))
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(marketChart)
}
}

Related

Why doesn't Metal render my simple clear window code?

I have been following this tutorial. I downloaded the source and tried "translating" it to Swift. This is my "translated" code:
import Cocoa
import AppKit
import MetalKit
import simd
class MetalViewController: NSViewController {
#IBOutlet var inview: MTKView!
override func viewDidLoad() {
super.viewDidLoad()
let _view: MTKView = self.inview
_view.device = MTLCreateSystemDefaultDevice()
let _renderer: Renderer=initView(view: _view)
_view.delegate=_renderer as? MTKViewDelegate
_view.preferredFramesPerSecond=60
}
}
class Renderer: NSObject {
init(device: MTLDevice){
self._device=device
self._commandQueue=_device.makeCommandQueue()!
super.init()
}
func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {
}
func draw(in view: MTKView) {
let color = Color(red: 1.0,green: 0.0,blue: 0.0,alpha: 0.0)
view.clearColor = MTLClearColorMake(color.red, color.green, color.blue, color.alpha)
let commandbuffer = _commandQueue.makeCommandBuffer()
let renderpassdescriptor: MTLRenderPassDescriptor = view.currentRenderPassDescriptor!
let renderencoder: MTLRenderCommandEncoder = (commandbuffer?.makeRenderCommandEncoder(descriptor: renderpassdescriptor))!
renderencoder.endEncoding()
commandbuffer!.present(view.currentDrawable!)
commandbuffer!.commit()
}
var _device: MTLDevice
var _commandQueue: MTLCommandQueue
}
struct Color{
var red, green, blue, alpha: Double
}
func initView(view: MTKView) -> Renderer{
var renderer: Renderer
renderer=Renderer(device: view.device!)
return renderer
}
So I put the AAPLRenderer and AAPLViewControllers into one file, and made it so that there are no header files. I linked the view with #IBOutlet to the view controller because the view was a NSView and I cannot cast it to MTKView without getting a compile time error. The AppDelegate is the original one and I do not have a main file.
I end up with a window that does not show red, but rather shows nothing. I do not understand why this is happening. Please help me, thank you.
I see two issues.
1) MTKView's delegate property is a weak var, which means that if you don't hold onto an instance of your renderer, it'll be immediately deinited and never receive any delegate callbacks. Keep a reference to your renderer as a property on your view controller.
class MetalViewController: NSViewController {
#IBOutlet var inview: MTKView!
var renderer: Renderer!
override func viewDidLoad() {
// ...
let view: MTKView = self.inview
// ...
renderer = initView(view: view)
view.delegate = renderer
// ...
}
}
2) Because the Renderer class doesn't explicitly declare conformance to the MTKViewDelegate protocol, the conditional cast when assigning it as the view's delegate fails. Make Renderer explicitly conform to the protocol, and remove the conditional cast as shown above.
class Renderer: NSObject, MTKViewDelegate
Well, it could be anything. But, the first thing I would check is that your alpha setting for that red color should have alpha = 1.0 and not alpha = 0.0.

Make an image clickable to expand

I have a background image that I would like to expand when clicked. I have setup animations that will dim the background and prop the image to the center, but for some reason the image is not clickable.
I have tried to implement a simple print(tapped) and when I tap I dont see anything as well. I am wondering if I have to declare my image view as something else?
import Foundation
import UIKit
class JobViewController: UIViewController {
let imageView: UIImageView = {
let iv = UIImageView(image: #imageLiteral(resourceName: "yo"))
iv.contentMode = .scaleAspectFill
iv.isUserInteractionEnabled = true
iv.translatesAutoresizingMaskIntoConstraints = false
iv.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleZoomTap)))
return iv
}()
#objc func handleZoomTap(_ tapGesture: UITapGestureRecognizer) {
print("tap tap")
}
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(imageView)
imageView.fillSuperview()
}
}
When I tap the image, I expect that it should at least print "tap tap"
Is there something else that i am missing?
Delete this line:
iv.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleZoomTap)))
And add this to your viewDidLoad:
imageView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleZoomTap)))

Reuse Code to set image

i´m developing an app that has a lot of view controllers and did set the back ground image with code, but i have to copy and paste that block of code in every view controller, how can i type it once and call it to reuse the code in every view controller..Thanks A lot.
var imageView: UIImageView!
let image = UIImage(named: "backGroundImage.png")!
override func loadView() {
super.loadView()
self.imageView = UIImageView(frame: CGRectZero)
self.imageView.contentMode = .ScaleAspectFill
self.imageView.image = image
self.view.addSubview(imageView)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.imageView.frame = self.view.bounds
}
What you can do is make a parent UIViewController class and have all of your view controllers inherit from that class. Somethig like this:
class MyParentViewController: UIViewController {
var imageView: UIImageView!
let image = UIImage()
override func viewDidLoad() {
super.viewDidLoad()
self.imageView = UIImageView(frame: CGRectZero)
self.imageView.contentMode = .ScaleAspectFill
self.imageView.image = image
self.view.addSubview(imageView)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.imageView.frame = self.view.bounds
}
}
And then your child view controllers that enherit from this class would look something like this:
class MyViewController: MyParentViewController {
overide func viewDidLoad() {
image = UIImage(named:"My image name")
super.viewDidLoad()
}
}
Now, here is really the way you should do it
However, having multiple view controllers that are all the same probably isnt a good idea. I would just keep only the parent view controller (rename it obviously) and just change the value of "image" in the segue that leads to the view to whatever image you want. This would eliminate the need to have a ton of view controllers, and will make it easier to add more images in the future if you want.
Here's how I would do it:
protocol ImageViewBackground {
var backgroundImageView: UIImageView? {get set}
mutating func setBackgroundImage(image: UIImage)
}
extension ImageViewBackground where Self: UIViewController {
mutating func setBackgroundImage(image: UIImage) {
let backgroundImageView = self.backgroundImageView ?? setupImageView()
backgroundImageView.image = image
}
mutating func setupImageView() -> UIImageView {
let imageView = UIImageView(frame: self.view.frame)
imageView.contentMode = .ScaleAspectFill
view.addSubview(imageView)
backgroundImageView = backgroundImageView
return imageView
}
}
Then just make any UIViewController adhere to the protocol like so:
class ViewController: UIViewController, ImageViewBackground {
var backgroundImageView: UIImageView?
}
Then you can call setBackgroundImage from anywhere in your VC without having to make a generic subclass just for the background image.

Xcode Swift image zoom gesture

Hope someone can help me. Im trying to make a zoom gesture, so when the image are presented the user can zoom the image with fingers.
My code to present the image are:
// MARK: Show image full screen
func imageTapped(img: AnyObject) {
self.navigationController?.navigationBarHidden = true
let imageView = productImage as UIImageView
let newImageView = UIImageView(image: imageView.image)
newImageView.frame = self.view.frame
newImageView.backgroundColor = .blackColor()
newImageView.contentMode = .ScaleToFill
newImageView.userInteractionEnabled = true
let tap = UITapGestureRecognizer(target: self, action: "dismissFullscreenImage:")
newImageView.addGestureRecognizer(tap)
self.view.addSubview(newImageView)
}
func dismissFullscreenImage(sender: UITapGestureRecognizer) {
sender.view?.removeFromSuperview()
self.navigationController?.navigationBarHidden = false
}
Use UIScrollView and add UIImgeView in scroll view
import UIKit
class ViewController: UIViewController,UIScrollViewDelegate
{
var scrollV : UIScrollView!
var imageView : UIImageView!
override func viewDidLoad()
{
super.viewDidLoad()
self.navigationController?.navigationBarHidden = true
scrollV=UIScrollView()
scrollV.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height)
scrollV.minimumZoomScale=1
scrollV.maximumZoomScale=3
scrollV.bounces=false
scrollV.delegate=self;
self.view.addSubview(scrollV)
imageView=UIImageView()
imageView.image = UIImage(imageLiteral: "neymar.jpg")
imageView.frame = CGRectMake(0, 0, scrollV.frame.width, scrollV.frame.height)
imageView.backgroundColor = .blackColor()
imageView.contentMode = .ScaleToFill
scrollV.addSubview(imageView)
}
func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView?
{
return imageView
}
}
Take gesture programmatically and make its method and write down this code in the method.
pinchRecognizerOnView() is my method name. Take one view or image view inside view controller and add this new view in that.Now apply gesture method on this new view.
func pinchRecognizerOnView(sender: UIPinchGestureRecognizer!) {
sender.view?.transform = CGAffineTransformScale((sender.view?.transform)!, sender.scale, sender.scale)
sender.scale = 1
// its for zoom in out screen
}

Replace NSViewController under Swift2 Storyboard MAC OSX

I am new to Mac OSX and with Apple promoting the fact that the bodies of code are becoming similar decided to tell the folk I am writing code for we should be able to do a Mac OSX version. iPhone and iPad versions are all good and about to release second version so no issues there.
So I am subclassing NSWindowController to get access to the Toolbar and worked out how to remove and add items on the toolbar, but for the life of me I can not get one NSViewController (firstViewController) to dismiss and bring up the second NSViewController (secondViewController) in the same NSWindowController.
So the 2 issues are that
1. I want to be able to performSegueWithIdentifier from the first NSViewController in code and
2. bring up the second NSViewController by replacing the first NSViewController in the same NSWindowController.
If I add a button to the firstViewController and put a segue to the secondViewController then when I select the button the secondViewController comes up just fine but in a seperate window not the same NSWindowController that I want it to and the firstViewController does not get replaced but stays in the NSWindowController.
So I know the segue idea will work but its not working in code and when I do insert the segue from a button it works but into a seperate NSViewController that is not part of the NSWindowController.
I am trying to find some programming guide from Apple on the issue but no luck so far.
Here is an overview from my Storyboard:
Here is my NSWindowController subclassed and the func loginToMe2Team is trigger from the NSToolBar and its working just find as the print statements show up on the console.
import Cocoa
class me2teamWindowsController: NSWindowController {
#IBOutlet var mySignUp : NSToolbarItem!
#IBOutlet var myToolbar : NSToolbar!
let controller = ViewController()
override func windowDidLoad() {
super.windowDidLoad()
print("window loaded")
}
override func windowWillLoad() {
print("window will load")
}
#IBAction func logInToMe2Team(sender: AnyObject){
controller.LogIn() //THIS IS THE FUNC I AM TESTING WITH
}
#IBAction func signUpToMe2Team(sender: AnyObject){
controller.signUp()
}
Here is my NSViewController subclassed with the func LogIn. Its getting selected just fine but the performSegueWithIdentifier is not. And I did cut and past the Identifier to make absolutely sure it was the same.
import Cocoa
import WebKit
class ViewController: NSViewController {
#IBOutlet weak var theWebPage: WebView!
#IBOutlet weak var progressIndicator: NSProgressIndicator!
override func viewDidLoad() {
super.viewDidLoad()
let urlString = "https://thewebpage.com.au"
self.theWebPage.mainFrame.loadRequest(NSURLRequest(URL: NSURL(string: urlString)!))
}
override func viewDidAppear() {
}
func LogIn() {
print("I logged in")
self.performSegueWithIdentifier("goToTeamPage", sender: self)
//THIS IS THE BIT THATS NOT WORKING
}
func signUp() {
print("I have to sign up now")
}
override var representedObject: AnyObject? {
didSet {
}
}
func webView(sender: WebView!, didStartProvisionalLoadForFrame frame: WebFrame!)
{
self.progressIndicator.startAnimation(self)
}
func webView(sender: WebView!, didFinishLoadForFrame frame: WebFrame!)
{
self.progressIndicator.stopAnimation(self)
}
}
You need to use a custom segue class (or possibly NSTabViewController if it’s enough for your needs). Set the segue’s type to Custom, with your class name specified:
…and implement it. With no animation, it’s simple:
class ReplaceSegue: NSStoryboardSegue {
override func perform() {
if let src = self.sourceController as? NSViewController,
let dest = self.destinationController as? NSViewController,
let window = src.view.window {
// this updates the content and adjusts window size
window.contentViewController = dest
}
}
}
In my case, I was using a sheet and wanted to transition to a different sheet with a different size, so I needed to do more:
class ReplaceSheetSegue: NSStoryboardSegue {
override func perform() {
if let src = self.sourceController as? NSViewController,
let dest = self.destinationController as? NSViewController,
let window = src.view.window {
// calculate new frame:
var rect = window.frameRectForContentRect(dest.view.frame)
rect.origin.x += (src.view.frame.width - dest.view.frame.width) / 2
rect.origin.y += src.view.frame.height - dest.view.frame.height
// don’t shrink visible content, prevent minsize from intervening:
window.contentViewController = nil
// animate resizing (TODO: crossover blending):
window.setFrame(window.convertRectToScreen(rect), display: true, animate: true)
// set new controller
window.contentViewController = dest
}
}
}

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