Question

有人可以告诉我为什么在声明let = Gradient

时我有错误

contectual type CFArray can not be used with array literal

使用此代码 - 这只是一个背景渐变，我认为这比使用矢量更好..

override func drawRect(rect: CGRect) {

    //// General Declarations
    let context = UIGraphicsGetCurrentContext()

    //// Color Declarations
    let gradientColor = UIColor(red: 0.180, green: 0.808, blue: 0.831, alpha: 0.196)
    let gradientColor2 = UIColor(red: 0.200, green: 0.282, blue: 0.392, alpha: 1.000)

    //// Gradient Declarations
    let gradient = CGGradientCreateWithColors(CGColorSpaceCreateDeviceRGB(), [gradientColor2.CGColor, gradientColor2.blendedColorWithFraction(0.5, ofColor: gradientColor).CGColor, gradientColor.CGColor], [0, 1, 1])!

    //// Rectangle Drawing
    let rectanglePath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 375, height: 667))
    CGContextSaveGState(context)
    rectanglePath.addClip()
    CGContextDrawLinearGradient(context, gradient, CGPoint(x: 187.5, y: -0), CGPoint(x: 187.5, y: 667), CGGradientDrawingOptions())
    CGContextRestoreGState(context)



}

}

Answer 1

所以这意味着你不能将swift数组传递给CGGradientCreateWithColors函数。您需要在CFArray中转换该数组，如下所示：

let gradientArray = [gradientColor2.CGColor, gradientColor.CGColor]
let arrayPointer = UnsafeMutablePointer<UnsafePointer<Void>>(gradientArray)
let cfArray = CFArrayCreate(nil, arrayPointer, gradientArray.count, nil)

然后将CFArray引用传递给函数：

let gradient = CGGradientCreateWithColors(CGColorSpaceCreateDeviceRGB(), cfArray, [0, 1, 1])!

核心图形＆amp;渐变

1 个答案: