从字符串中提取 RGB 值

Question

如何从以下字符串中提取 RBG 值？:

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

我想从 background-color 值中提取 "rgb(230, 0, 0)"，这样我就可以将它转换为十六进制字符串并更新一些 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?

Answer 1

let range = (string as NSString).range(of: "\"background-color: ")
let startPoint = range.location + range.length
let subString = (string as NSString).substring(from: startPoint)
let deliminator = ";"
let components = subString.components(separatedBy: deliminator)
let rgb = components[0]

print(rgb) -> "rgb(230, 0, 0)"

Answer 2

您可以使用 regex 来获取两个字符串之间的字符串：

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[[=10=]])}) {
    print(rgb)  // "rgb(230, 0, 0)"
}

从字符串中提取 RGB 值

Extracting the RGB value from a string

rgb

ios

swift