Swift 中的 UIBezierPath：路径非常奇怪地关闭

Question

我正在使用的扩展来插入 U 形绘图。不幸的是，路径以一种奇怪的方式关闭：

它应该是什么样子：

实际情况：

我的代码：

override func drawRect(rect: CGRect) {
    let points: [CGPoint] = [CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75), CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75), CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75)]

    let path = UIBezierPath(hermiteInterpolatedPoints: points, closed: false)

    if let path = path {
        UIColor.blueColor().set()
        path.lineWidth = 5.0
        path.stroke()
    } 
}

当数组缩短为：

let points: [CGPoint] = [CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108)]

看起来像这样：

Answer 1

你的点数组是相同的 16 个点重复三次。

let points: [CGPoint] = [
    CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75),
    CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75),
    CGPoint(x: 78, y: 99), CGPoint(x: 78, y: 128), CGPoint(x: 78, y: 173), CGPoint(x: 84, y: 199), CGPoint(x: 95, y: 223), CGPoint(x: 112, y: 240), CGPoint(x: 136, y: 243), CGPoint(x: 170, y: 236), CGPoint(x: 203, y: 217), CGPoint(x: 227, y: 190), CGPoint(x: 240, y: 160), CGPoint(x: 241, y: 134), CGPoint(x: 241, y: 108), CGPoint(x: 240, y: 93), CGPoint(x: 239, y: 84), CGPoint(x: 237, y: 75)
]

您从最后一点 CGPoint(x: 237, y: 75) 跳回起点 CGPoint(x: 78, y: 99)（并且您这样做了两次），这将关闭路径。

对于将相同的点序列重复三次的数组，路径是正确的。

Swift 中的 UIBezierPath：路径非常奇怪地关闭

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