user7166107
user7166107

Reputation:

how to draw text in center to uiimage?

I want to set my text Sold Out to the center in UIimage. but it not in center .

func textToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {

    let textColor = UIColor.white
    let textFont = UIFont(name: "Helvetica Bold", size: 32)!

    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)
    let rect = CGRect(origin: CGPoint(x:(image.size.width/2), y: (image.size.height/2)), size: image.size)

    text.draw(in: rect, withAttributes: textFontAttributes)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage!
}

caller function

 imageViewSoldStatus.image = textToImage(drawText: "Sold out", inImage: UIImage(named:"soldout.png")!, atPoint: CGPoint(x: 5.0, y: 5.0))

I have spent of very long time to solve this problem but I could not find any solution.

Red flag my image

enter image description here

above is the screen I obtained. below is the design that I want to achieve.

enter image description here

update

Marie Dm answerd used! it is text align center but not image center

enter image description here

Upvotes: 6

Views: 8564

Answers (3)

Marie Dm
Marie Dm

Reputation: 2727

Try this:

func textToImage(drawText text: NSString, inImage image: UIImage) -> UIImage? {
    //draw image first
    UIGraphicsBeginImageContext(image.size)
    image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
    
    //text attributes
    let font=UIFont(name: "Helvetica-Bold", size: 32)!
    let text_style=NSMutableParagraphStyle()
    text_style.alignment=NSTextAlignment.center
    let text_color=UIColor.white
    let attributes=[NSFontAttributeName:font, NSParagraphStyleAttributeName:text_style, NSForegroundColorAttributeName:text_color]

    //vertically center (depending on font)
    let text_h=font.lineHeight
    let text_y=(image.size.height-text_h)/2
    let text_rect=CGRect(x: 0, y: text_y, width: image.size.width, height: text_h)
    text.draw(in: text_rect.integral, withAttributes: attributes)
    let result=UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return result
}

Upvotes: 18

jerr bear
jerr bear

Reputation: 21

updated for Swift 5

func textToImage(drawText text: NSString, inImage image: UIImage) -> UIImage {
    UIGraphicsBeginImageContext(image.size)
    image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
    let font=UIFont(name: "Helvetica-Bold", size: 14)!
    let text_style=NSMutableParagraphStyle()
    text_style.alignment=NSTextAlignment.center
    let text_color=UIColor.white
    let attributes=[NSAttributedString.Key.font:font, NSAttributedString.Key.paragraphStyle:text_style, NSAttributedString.Key.foregroundColor:text_color]
    let text_h=font.lineHeight
    let text_y=(image.size.height-text_h)/2
    let text_rect=CGRect(x: 0, y: text_y, width: image.size.width, height: text_h)
    text.draw(in: text_rect.integral, withAttributes: attributes)
    let result=UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return result!
}

Upvotes: 2

cvb
cvb

Reputation: 1755

Marie's answer updated for swift 4

func textToImage(drawText text: NSString, inImage image: UIImage) -> UIImage {
        UIGraphicsBeginImageContext(image.size)
        image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
        let font=UIFont(name: "Helvetica-Bold", size: 14)!
        let text_style=NSMutableParagraphStyle()
        text_style.alignment=NSTextAlignment.center
        let text_color=UIColor.white
        let attributes=[NSAttributedStringKey.font:font, NSAttributedStringKey.paragraphStyle:text_style, NSAttributedStringKey.foregroundColor:text_color]
        let text_h=font.lineHeight
        let text_y=(image.size.height-text_h)/2
        let text_rect=CGRect(x: 0, y: text_y, width: image.size.width, height: text_h)
        text.draw(in: text_rect.integral, withAttributes: attributes)
        let result=UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return result!
    }

Upvotes: 0

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