没有'|'候选人产生预期的上下文结果类型 'CGGradientDrawingOptions'

Question

回顾一个旧项目，我打算添加一些功能，运行到这个错误中。有谁知道如何消除这个？它发生在以下代码中：

UInt32(CGGradientDrawingOptions.DrawsBeforeStartLocation) | UInt32(CGGradientDrawingOptions.DrawsAfterEndLocation))

完整文件如下：

import UIKit

class BackgroundView: UIView {

    override func drawRect(rect: CGRect) {

        // Background View

        //// Color Declarations
        var lightPurple: UIColor = UIColor(red: 0.377, green: 0.075, blue: 0.778, alpha: 1.000)
        var darkPurple: UIColor = UIColor(red: 0.060, green: 0.036, blue: 0.202, alpha: 1.000)

        let context = UIGraphicsGetCurrentContext()

        //// Gradient Declarations
        let purpleGradient = CGGradientCreateWithColors(CGColorSpaceCreateDeviceRGB(), [lightPurple.CGColor, darkPurple.CGColor], [0, 1])

        //// Background Drawing
        let backgroundPath = UIBezierPath(rect: CGRectMake(0, 0, self.frame.width, self.frame.height))
        CGContextSaveGState(context)
        backgroundPath.addClip()
        CGContextDrawLinearGradient(context, purpleGradient,
            CGPointMake(160, 0),
            CGPointMake(160, 568),
            UInt32(CGGradientDrawingOptions.DrawsBeforeStartLocation) | UInt32(CGGradientDrawingOptions.DrawsAfterEndLocation))
        CGContextRestoreGState(context)

    }
}

Answer 1

尝试将它们分组到 Array 中。

Answer 2

CGGradientDrawingOptions 自 Swift 2.0 implements OptionSetType。这意味着不再需要 | 运算符，您可以这样写：

let options: CGGradientDrawingOptions = [.DrawsBeforeStartLocation, .DrawsAfterEndLocation]

要获取更多信息，您可以go here

没有'|'候选人产生预期的上下文结果类型 'CGGradientDrawingOptions'

No '|' candidates produce the expected contextual result type 'CGGradientDrawingOptions'

xcode

ios

swift

swift2