Swift：如何将String列表转换为CGPoint列表？

Question

我是一个Swift的新手，并没有在网上找到任何东西。如何转换格式为这样的字符串：

let str:String = "0,0 624,0 624,-48 672,-48 672,192" 

要CGPoint的数组？

Answer 1

该解决方案使用iOS提供的CGPointFromString功能。

import UIKit 

let res = str 
    .components(separatedBy: " ") 
    .map { CGPointFromString("{\($0)}") } 

Answer 2

我不知道，像这样？

let str:String = "0,0 624,0 624,-48 672,-48 672,192" 

let pointsStringArray = str.componentsSeparatedByString(" ") 
var points = [CGPoint]() 
for pointString in pointsStringArray { 
    let xAndY = pointString.componentsSeparatedByString(",") 
    let xString = xAndY[0] 
    let yString = xAndY[1] 
    let x = Double(xString)! 
    let y = Double(yString)! 
    let point = CGPoint(x: x, y: y) 
    points.append(point) 
} 
print(points) 

当然，它是不安全的，并且不处理所有条件。但是，这应该带你走向正确的方向。

Answer 3

这是一个更加实用的方法。需要添加错误检查。

import Foundation 

let str = "0,0 624,0 624,-48 672,-48 672,192" 

let pointStrings = str.characters //get the character view 
       .split{$0 == " "} //split the pairs by spaces 
       .map(String.init) //convert the character views to new Strings 

let points : [CGPoint] = pointStrings.reduce([]){ //reduce into a new array 
        let pointStringPair = $1.characters 
              .split{$0 == ","} //split pairs by commas 
              .map(String.init) //convert the character views to new Strings 
        let x = CGFloat(Float(pointStringPair[0])!) //get the x 
        let y = CGFloat(Float(pointStringPair[1])!) //get the y 
        return $0 + [CGPoint(x: x, y: y)] //append the new point to the accumulator 
       } 
print(points)