将文本添加到UIImage SWIFT IOS 11

Question

I have an image saved in a UIImageView.image variable name ImageView. I'm trying to get text simply added to the ImageView.image so it simply shows the picture with the words "Hello".

I've tried the following and NONE of them work. I just get the same exact image back. I've been at this for days now and I have gotten very frustrated with the non working answers on Stack Overflow: Code I've tried:

    ImageView.Image = textToImage(drawText: "Hello", inImage: ImageView.image!, atPoint: CGPoint(x: 20, y: 20))
    ImageView.image = generateImageWithText(text: "Hello")

func textToImage(drawText text: String, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {
    let textColor = UIColor.white
    let textFont = UIFont(name: "Marker Felt", size: 12)!
    let scale = image.scale
        //UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)

    let textFontAttributes = [
        NSAttributedStringKey.font: textFont,
        NSAttributedStringKey.foregroundColor: textColor,
        ] as [NSAttributedStringKey : Any]
    image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))

    let rect = CGRect(origin: point, size: image.size)
    text.draw(in: rect, withAttributes: textFontAttributes)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    //CameraImageView.image = newImage
    UIGraphicsEndImageContext()

    return newImage!
}

func generateImageWithText(text: String) -> UIImage
{
    let image = CameraImageView.image

    let imageView = UIImageView(image: image)
    imageView.backgroundColor = UIColor.clear
    imageView.frame = CGRect(origin: CGPoint(x: 0, y: 0), size: (image?.size)!)

    let label = UILabel(frame: CGRect(origin: CGPoint(x: 20, y: 20), size: CGSize(width: 3024.0, height: 4032.0)/*(width://image?.size)!*/))
    label.backgroundColor = UIColor.clear
    label.textAlignment = .center
    label.textColor = UIColor.white
    label.text = text

    UIGraphicsBeginImageContextWithOptions(label.bounds.size, false, 0)
    imageView.layer.render(in: UIGraphicsGetCurrentContext()!)
    label.layer.render(in: UIGraphicsGetCurrentContext()!)
    let imageWithText = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext();

    return imageWithText!
}

Answer 1

Here's a demo:

Here's the complete code:

class ViewController: UIViewController {
    @IBOutlet weak var iv: UIImageView!
    @IBOutlet weak var tf: UITextField!

    @IBAction func doGo(_ sender: Any) {
        let s = tf.text!
        let s2 = NSAttributedString(string: s, attributes: 
            [.font:UIFont(name: "Georgia", size: 100)!, 
             .foregroundColor: UIColor.yellow])
        let sz = iv.image!.size
        let r = UIGraphicsImageRenderer(size:sz)
        iv.image = r.image {
            _ in
            iv.image!.draw(at:.zero)
            s2.draw(at: CGPoint(x:30, y:sz.height-150))
        }
    }
    @IBAction func doRevert(_ sender: Any) {
        config()
    }
    func config() {
        iv.image = UIImage(named:"nice.jpg")
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        config()
    }
}

Go ye and do likewise.

Answer 2

// adding text to image

    let titleLabel = UILabel(frame: CGRect(x: 10, y: 0, width: imageView.frame.width - 10, height: 30))
    titleLabel.text = "userName"
    titleLabel.textColor = UIColor.black
    titleLabel.font = UIFont(name:"chalkboard SE", size: 18)
    imageView.addSubview(titleLabel)

Answer 3

Ok, I figured it out. It has to do with the UIImageView field being dynamic. I capture an image from the camera and saved it into the CameraImageView.image, which is then saved into another UIImage variable. You can NOT add text to this type of image as the app doesn't know what kind of image it is (ie .jpg/.PNG, etc).

If the image is saved as a HARD image in the app (in the assets folder), then you can add text to the image. Since no image is saved in the assets folder the app simply does nothing as it doesn't know what to do.

I created a blank/clear png file and saved it in the assets folder. I then combined that saved image with the image from the CameraImage into another UIImage variable and displayed that.

Here's the Code:

    let bottomImage = CameraImageView.image
    var topImage = UIImage(named: "HelloWorld.png")
    let size = CGSize(width: 242, height: 243)

    UIGraphicsBeginImageContext(size)
    let areaSize = CGRect(x: 0, y: 0, width: size.width, height: size.height)
    bottomImage!.draw(in: areaSize)
    topImage!.draw(in: areaSize, blendMode: CGBlendMode(rawValue: 0)!, alpha: 0.8)

    //the constant below is what takes the 2 images from the context and merges them into 1 new image
    let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()!

    //set the combined image into the empty Imageview variable, and then display it
    ImageViewEmpty.image = newImage
    UIGraphicsEndImageContext()
    ImageViewEmpty.isHidden = false