Swift: Adding text to image does not work

Question

I'm trying to edit an image by adding text to it, but the code I got from this post does not work: How to write text on image in Objective-C (iOS)?

My image-editing code looks like this:

func addTextToImage(image:UIImage, text:NSString, pointof: CGPoint) -> UIImage{

    let font:UIFont = UIFont.boldSystemFontOfSize(12)

    let dict:NSDictionary = [NSFontAttributeName : font]

    UIGraphicsBeginImageContext(image.size)
    image.drawInRect(CGRectMake(0, 0, image.size.width, image.size.height))
    let rect: CGRect = CGRectMake(pointof.x, pointof.y, image.size.width, image.size.height)
    let color: UIColor = UIColor.whiteColor()
    text.drawInRect(CGRectIntegral(rect), withAttributes:dict)

    let newImage:UIImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage
}

And then I use the textViewDidChange method to add the text to the image, but it does not work:

func textViewDidChange(textView: UITextView){
    backgroundImage.image = addTextToImage(imageToView, text: textViewer.text, pointof: CGPointMake(0, 0))
}

Any suggestions on what I'm doing wrong would be appreciated.

First we need to know what is wrong. "Does not work" is not helpful. What result does you code give? Is textViewDidChange being called? Is newImage actually created? — rdelmar, Feb 09 '15 at 23:50
@rdelmar Nothing happens, textViewDidChange is being called and therefore I assume it's being created. — martin, Feb 09 '15 at 23:53
Don't assume. Put a print statement in just before "return newImage", and see if newImage is non-nil. — rdelmar, Feb 09 '15 at 23:54
@rdelmar Okay, I did so, and both functions are being called and the new image created is not empty. — martin, Feb 10 '15 at 00:00
Your code works for me, but the text is black, not white. If you want white text, you need to add the NSForegroundColorAttributeName key to your attributes dictionary. — rdelmar, Feb 10 '15 at 00:09
@rdelmar Now it works for me too, I don't know what I did really, now the only problem is the white color, which I now see is not being set anywhere in my code. Do you know how to do this? — martin, Feb 10 '15 at 00:18

score 0 · Answer 1 · answered Dec 07 '17 at 06:42

func addTextToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint) -> UIImage
{
    let textColor = UIColor.blue

    let textFont = UIFont(name: "ChalkboardSE-Regular", size: 26)!

    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)

    let textFontAttributes = [
        NSFontAttributeName: textFont,
        NSForegroundColorAttributeName: textColor,
        ] as [String : 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()
    UIGraphicsEndImageContext()

    return newImage!
}

Swift: Adding text to image does not work

1 Answers1