Screenshot a view with label and transparent background in iOS and upload it to server

Question

I want to screenshot a view and create an UIImage from it. I want the transparency attribute of the view to be maintained in my image. I tried this method after creating an extension of UIImage but the background is not transparent in the resultant image when uploaded to the server.

Kindly help or point me if I am doing something wrong!! This means that the resultant png was not having transparency.

class func createTransparentImageFrom(label: UILabel, imageSize: CGSize) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(imageSize, false, 2.0)
    let currentView = UIView.init(frame: CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height))
    currentView.backgroundColor = UIColor.clear
    currentView.addSubview(label)

    currentView.layer.render(in: UIGraphicsGetCurrentContext()!)
    let img = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return img!
}

Answer 1

This was due to the fact that when we render a view the image is JPEG/JPG, so we need to convert it to png in order to get layer information.

Try this :

extension UIImage {
 class func createTransparentPNGFrom(label: UILabel, imageSize: CGSize) -> UIImage? {
    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
    let currentView = UIView.init(frame: CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height))
    currentView.backgroundColor = UIColor.clear
    currentView.addSubview(label)
    currentView.layer.render(in: UIGraphicsGetCurrentContext()!)
    let img = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    guard let newImg = img else {
        return nil
    }
    guard let imageData = UIImagePNGRepresentation(newImg) else {
        return nil
    }
    return UIImage.init(data: imageData)
 }
}

Answer 2

Swift 5 UIImage extension: screen UIView with transparent background

• this is for taking a screenshot of a view which should have .backgroundColor = .clear

extension UIView {

    func takeSnapshotOfView() -> UIImage? {

        let size = CGSize(width: frame.size.width, height: frame.size.height)
        let rect = CGRect.init(origin: .init(x: 0, y: 0), size: frame.size)

        UIGraphicsBeginImageContext(size)
        drawHierarchy(in: rect, afterScreenUpdates: true)

        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        guard let imageData = image?.pngData() else {
           return nil
        }

        return UIImage.init(data: imageData)
    }

}

Answer 3

You need to put opaque value true for transparent result Extension of UIView Of transparent screenshot

func screenShot() -> UIImage? {
     UIGraphicsBeginImageContextWithOptions(self.bounds.size, true, UIScreen.main.scale)
     self.layer.render(in: UIGraphicsGetCurrentContext()!)
     let img = UIGraphicsGetImageFromCurrentImageContext()
     UIGraphicsEndImageContext()
     return img
 }