how to add text using pkcanvasview in swift

To add text using PKCanvasView, you can use the UIGraphicsImageRenderer class to create a UIImage representation of the PKCanvasView's current drawing, and then add the text to the image. Here is an example of how to add text to a PKCanvasView:


main.swift
// Assume that canvas is an instance of PKCanvasView
let renderer = UIGraphicsImageRenderer(size: canvas.bounds.size)
let image = renderer.image { ctx in
    canvas.drawHierarchy(in: canvas.bounds, afterScreenUpdates: true)
}

// Create a mutable copy of the image
guard let cgImage = image.cgImage else { return }
let mutableCgImage = cgImage.mutableCopy()!

// Add text to the image using Core Text
guard let context = CGContext(data: nil, width: Int(canvas.bounds.width), height: Int(canvas.bounds.height),
                              bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: cgImage.bytesPerRow,
                              space: cgImage.colorSpace!, bitmapInfo: cgImage.bitmapInfo.rawValue) else { return }
context.draw(cgImage, in: CGRect(x: 0, y: 0, width: canvas.bounds.width, height: canvas.bounds.height))

let text = "Hello, world!"
let textLayer = CATextLayer()
textLayer.frame = CGRect(x: 50, y: 50, width: 200, height: 50)
textLayer.string = text
textLayer.foregroundColor = UIColor.black.cgColor
textLayer.backgroundColor = UIColor.clear.cgColor
textLayer.alignmentMode = kCAAlignmentCenter
textLayer.contentsScale = UIScreen.main.scale

// Apply the text layer to the context
context.addSublayer(textLayer)

// Create a new UIImage from the context
let modifiedImage = UIImage(cgImage: context.makeImage()!)

// Set the modified image to the canvas
canvas.drawing = PKDrawing(image: modifiedImage)
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In this example, we first create a UIImage representation of the PKCanvasView's current drawing using the UIGraphicsImageRenderer class. We then create a mutable copy of the image, and add text to it using a CATextLayer. Finally, we create a new UIImage from the modified context, and set it as the PKCanvasView's drawing.

Note that this is just one way to add text to a PKCanvasView, and there may be other methods that are more suitable for your specific use case.

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