有一个问题的答案正好相反: 如何使用Regex.Replace从字符串中删除数字?

// Pull out only the numbers from the string using LINQ

var numbersFromString = new String(input.Where(x => x >= '0' && x <= '9').ToArray());

var numericVal = Int32.Parse(numbersFromString);

这是我的解决方案

string var = "Hello345wor705Ld";
string alpha = string.Empty;
string numer = string.Empty;
foreach (char str in var)
{
    if (char.IsDigit(str))
        numer += str.ToString();
    else
        alpha += str.ToString();
}
Console.WriteLine("String is: " + alpha);
Console.WriteLine("Numeric character is: " + numer);
Console.Read();

下面是Linq版本:

string s = "123iuow45ss";
var getNumbers = (from t in s
                  where char.IsDigit(t)
                  select t).ToArray();
Console.WriteLine(new string(getNumbers));

你可以像下面这样使用String属性:

 return new String(input.Where(Char.IsDigit).ToArray()); 

它只给出字符串中的数字。

string s = "kg g L000145.50\r\n";
        char theCharacter = '.';
        var getNumbers = (from t in s
                          where char.IsDigit(t) || t.Equals(theCharacter)
                          select t).ToArray();
        var _str = string.Empty;
        foreach (var item in getNumbers)
        {
            _str += item.ToString();
        }
        double _dou = Convert.ToDouble(_str);
        MessageBox.Show(_dou.ToString("#,##0.00"));

只需使用一个RegEx来匹配字符串，然后转换:

Match match = Regex.Match(test , @"(\d+)");
if (match.Success) {
   return int.Parse(match.Groups[1].Value);
}