在多行UIButton的文本中查找字母的运行时位置

// 获取UIButton的文本内容
let buttonText = button.titleLabel?.text ?? ""

// 将文本内容转换为NSString类型
let buttonTextNSString = buttonText as NSString

// 创建字母字符集
let letterCharacterSet = NSCharacterSet.letterCharacterSet()

// 查找字母的位置
var letterRanges = [NSRange]()
let lines = buttonTextNSString.componentsSeparatedByString("\n")
for line in lines {
    let lineRange = buttonTextNSString.rangeOfString(line)
    let letterRange = buttonTextNSString.rangeOfCharacterFromSet(letterCharacterSet, options: .CaseInsensitiveSearch, range: lineRange)
    while letterRange.location != NSNotFound {
        letterRanges.append(letterRange)
        let searchRange = NSMakeRange(letterRange.location + 1, lineRange.length - (letterRange.location - lineRange.location) - 1)
        letterRange = buttonTextNSString.rangeOfCharacterFromSet(letterCharacterSet, options: .CaseInsensitiveSearch, range: searchRange)
    }
}

// 打印字母的位置
for range in letterRanges {
    print("字母位置：\(range.location)，长度：\(range.length)")
}