How to insert image on UIView?

问题:

The code below prints a line on a UIView. I just want to know the code that I would write to be able to insert an image on top of the view.

import UIKit

class draw: UIView {
    var line = UIBezierPath()
    var line1 = UIBezierPath()

    func grapher() {
        line1.move(to: .init(x:0, y: bounds.height / 6))
        line1.addLine(to: .init(x: bounds.width, y: bounds.height / 6))
        UIColor.blue.setStroke()
        line1.lineWidth = 2
        line1.stroke()
    }

    override func draw(_ rect: CGRect) {
        grapher()
    }
}

回答1:

If you want to add image on view. Please use below code.

    let imageName = "yourImage.png"
    let image = UIImage(named: imageName)
    let imageView = UIImageView(image: image!)
    imageView.frame = CGRect(x: 0, y: 0, width: 100, height: 200)
    self.view.addSubview(imageView)
    //Imageview on Top of View
    self.view.bringSubview(toFront: imageView)

If you want to draw specific shape then Go with Core Graphics

https://developer.apple.com/documentation/coregraphics

https://cocoacasts.com/drawing-shapes-in-swift-with-paintcode/

https://www.ioscreator.com/tutorials/drawing-shapes-core-graphics-tutorial-ios10

回答2:

Add UIImage on the view layer

let myLayer = CALayer()
let myImage = UIImage(named: "star")?.cgImage
myLayer.frame = CGRect(x: 0, y: 0, width: 60, height: 60)
myLayer.contents = myImage
myView.layer.addSublayer(myLayer)

Add UIImage as a subView

let image = UIImage(named: "star")
let imageView = UIImageView(image: image!)
imageView.frame = CGRect(x: 0, y: 0, width: 60, height: 60)
myView.addSubview(imageView)

回答3:

Tested on swift 4

// This function should be called in/after viewDidAppear to let view render
    func addArrowImageToButton(button: UIButton, arrowImage:UIImage = #imageLiteral(resourceName: "my_arrow_image") ) {
        let btnSize:CGFloat = 32
        let imageView = UIImageView(image: arrowImage)
        let btnFrame = button.frame
        imageView.frame = CGRect(x: btnFrame.width-btnSize-8, y: btnFrame.height/2 - btnSize/2, width: btnSize, height: btnSize)
        button.addSubview(imageView)
        //Imageview on Top of View
        button.bringSubviewToFront(imageView)
    }

and call it this way in viewDidAppear

self.addArrowImageToButton(button: myButtonObject)