using System;
using System.Globalization;
public class ParseTest
{
 public static void Main()
 {
  string s1="123456";
  string s2="123456.78";
  string s3="$123.23";
  string s4="1.23456E+3";
  Console.WriteLine(int.Parse(s1));
  Console.WriteLine(double.Parse(s2));
  Console.WriteLine(double.Parse(s3,NumberStyles.AllowCurrencySymbol|NumberStyles.Float));
  Console.WriteLine(double.Parse(s4,NumberStyles.Float));
  Console.WriteLine(double.Parse(s3,NumberStyles.Any));
  Console.WriteLine(double.Parse(s4,NumberStyles.Any));
 }
}

NumberStyles.AllowCurrencySymbol
就是允许有字符