如何在UIImageView中更改單個像素的圖像

Question

我有一個UIImage ，我想改變它的特定像素的圖像，比如100 x 100像素。 我怎樣才能做到這一點？

Answer 1

您可以在該像素上添加一個矩形並用顏色填充：

var image: UIImage!
let color = UIColor.red
image = UIGraphicsImageRenderer(size: image.size).image { context in
    image.draw(at: .zero)
    let rectangle = CGRect(x: 100, y: 100, width: 1, height: 1)
    color.setFill()
    context.fill(rectangle)
}

或者也許你想在其他UIImage中嵌入一個1 x 1像素的UIImage：

var onePixel: UIImage!
var image: UIImage!
image = UIGraphicsImageRenderer(size: image.size).image { context in
    image.draw(at: .zero)
    onePixel.draw(at: CGPoint(x: 100, y: 100))
}

或許你想將UIImage的像素移動到另一個UIImage：

var image1: UIImage!
var image2: UIImage!
// 1 x 1 size image, from position 100 x 100 of image2
var pixel: UIImage = UIGraphicsImageRenderer(bounds: CGRect(x: 100, y: 100, width: 1, height: 1)).image(actions: { _ in
    image2.draw(at: .zero)
})
// The image1 with the pixel image embed in the position 100 x 100
var image1WithPixel = UIGraphicsImageRenderer(size: image1.size).image { (_) in
    image1.draw(at: .zero)
    pixel.draw(at: CGPoint(x: 100, y: 100))
}