如何在C#中对字符串中的某个数字进行倍增

using System;

class Program
{
    static void Main()
    {
        string input = "abc123def";
        int multiplier = 2;
        
        string result = MultiplyNumberInString(input, multiplier);
        
        Console.WriteLine(result);
    }
    
    static string MultiplyNumberInString(string input, int multiplier)
    {
        string result = "";
        string currentNumber = "";
        
        foreach (char c in input)
        {
            if (Char.IsDigit(c))
            {
                currentNumber += c;
            }
            else
            {
                if (currentNumber != "")
                {
                    int number = int.Parse(currentNumber);
                    int multipliedNumber = number * multiplier;
                    result += multipliedNumber.ToString();
                    currentNumber = "";
                }
                
                result += c;
            }
        }
        
        if (currentNumber != "")
        {
            int number = int.Parse(currentNumber);
            int multipliedNumber = number * multiplier;
            result += multipliedNumber.ToString();
        }
        
        return result;
    }
}