在Swift中用纯色创建UIImage [英] Create UIImage with solid color in Swift

问题描述

我想以编程方式创建一个由纯色填充的UIImage。任何人都知道如何在Swift中执行此操作？

I want to programmatically create an UIImage filled by a solid color. Anyone have an idea of how to do this in Swift?

推荐答案

另一个不错的解决方案， Swift 2.2 兼容，就是在UIImage中创建另一个构造函数，这样：

Another nice solution, Swift 2.2 compatible, is to create another constructor in UIImage, in this way:

public extension UIImage {
    public convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
        let rect = CGRect(origin: .zero, size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        color.setFill()
        UIRectFill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        guard let cgImage = image?.CGImage else { return nil }
        self.init(CGImage: cgImage)
    }  
}

这样你可以用这种方式创建自定义彩色图像：

In this way you can create the custom colored-image in this way:

let redImage = UIImage(color: .redColor())

或者，可选择使用自定义尺寸创建图像：

Or, optionally, create the image with a custom size:

let redImage200x200 = UIImage(color: .redColor(), size: CGSize(width: 200, height: 200))

Swift 3.0

public extension UIImage {
  public convenience init?(color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
    let rect = CGRect(origin: .zero, size: size)
    UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
    color.setFill()
    UIRectFill(rect)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    guard let cgImage = image?.cgImage else { return nil }
    self.init(cgImage: cgImage)
  }
}

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