从字符串中提取 RGB 值 [英] Extracting the RGB value from a string

问题描述

如何从以下字符串中提取 RBG 值?:

How would I extract the RBG value from the following string?:

let string = "

我想从 background-color 值中提取 "rgb(230, 0, 0)" ，所以我可以将它转换为十六进制字符串和更新一些用户界面.

I would like to get extract "rgb(230, 0, 0)" from the background-color value, so I can convert it to a hex string and update some UI.

let range = string.range(of: "\"background-color: ")
let startPoint = range.location + range.length
let subString = string.substring(from: startPoint)
//generating error claiming 'cannot convert value of type 'int' to expected argument type 'string.index'. 
//paused here to ask S.O b/c I do not think substrings is the best way to do this, maybe there is a library that extracts values from html elements, or regex?

推荐答案

您可以使用 regex 来获取字符串两个字符串之间:

You can use a regex to get the string between two strings:

let string = "<span style=\"background-color: rgb(230, 0, 0);\">"

let pattern = "(?<=background-color: )(.*)(?=;)"
if let rgb = string.range(of: pattern, options: .regularExpression).map({String(string[$0])}) {
    print(rgb)  // "rgb(230, 0, 0)"
}

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