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UIGraphicsBeginImageContext vs UIGraphicsImageRenderer
UIGraphicsBeginImageContextWithOptions has been deprecated from iOS17, and it will crash on iOS17 when the height or width of size argument is 0.
We should replace UIGraphicsBeginImageContextWithOptions with UIGraphicsImageRenderer.
Render an image with UIGraphicsBeginImageContext
swift
let bound = CGRect(x: 0, y: 0, width: 200, height: 200)
UIGraphicsBeginImageContextWithOptions(bound.size, false, UIScreen.main.scale)
if let context = UIGraphicsGetCurrentContext() {
UIColor.darkGray.setStroke()
context.stroke(bound)
UIColor(red: 158/255, green: 215/255, blue: 245/255, alpha: 1).setFill()
context.fill(CGRect(x: 1, y: 1, width: 140, height: 140))
let image = UIGraphicsGetImageFromCurrentImageContext()
}
UIGraphicsEndImageContext()
The above code creates the following image:
Render an image with UIGraphicsImageRenderer
Rendering the same image with UIGraphicsImageRenderer.
- [Optional] Create a UIGraphicsImageRendererFormat object and specify render parameters.
swift
let format = UIGraphicsImageRendererFormat.default()
format.opaque = true
- Create a UIGraphicsImageRenderer object, providing
size
arugment andformat
argument(optional).
If you don't provider format object, the render uses default format for the current device.
swift
let renderer = UIGraphicsImageRenderer(size: CGSize(width: 200, height: 200))
swift
let format = UIGraphicsImageRendererFormat.default()
format.opaque = false
let renderer = UIGraphicsImageRenderer(size: CGSize(width: 200, height: 200),format: format)
Call one of the three rendering methods and provide Core Graphics drawing instructions as the closure argument to execute the rendering.
- image(actions:) return a UIImage object.
swiftlet renderer = UIGraphicsImageRenderer(size: CGSize(width: 200, height: 200)) let image = renderer.image { (context) in UIColor.darkGray.setStroke() context.stroke(renderer.format.bounds) UIColor(red: 158/255, green: 215/255, blue: 245/255, alpha: 1).setFill() context.fill(CGRect(x: 1, y: 1, width: 140, height: 140)) }
- jpegData(withCompressionQuality:actions:) returns a JPEG-encoded Data object.
swiftlet renderer = UIGraphicsImageRenderer(size: CGSize(width: 200, height: 200)) let jpegData = renderer.jpegData(withCompressionQuality: 0.8) { context in UIColor.darkGray.setStroke() context.stroke(renderer.format.bounds) UIColor(red: 158/255, green: 215/255, blue: 245/255, alpha: 1).setFill() context.fill(CGRect(x: 1, y: 1, width: 140, height: 140)) } let image = UIImage(data: jpegData)
- pngData(actions:) returns a PNG-encoded Data object.
swiftlet renderer = UIGraphicsImageRenderer(size: CGSize(width: 200, height: 200)) let pngData = renderer.pngData { context in UIColor.darkGray.setStroke() context.stroke(renderer.format.bounds) UIColor(red: 158/255, green: 215/255, blue: 245/255, alpha: 1).setFill() context.fill(CGRect(x: 1, y: 1, width: 140, height: 140)) } let image = UIImage(data: pngData)