快速的Int32.Parse，比系统的快。

using System;
namespace CSharpConsole01
{
    public static class ExternClass
    {
        public static int MyParse(this string text)
        {
            text = text.PadLeft(10, '0');
            if (text[0] < '0' || text[0] > '9' ||
                text[1] < '0' || text[1] > '9' ||
                text[2] < '0' || text[2] > '9' ||
                text[3] < '0' || text[3] > '9' ||
                text[4] < '0' || text[4] > '9' ||
                text[5] < '0' || text[5] > '9' ||
                text[6] < '0' || text[6] > '9' ||
                text[7] < '0' || text[7] > '9' ||
                text[8] < '0' || text[8] > '9' ||
                text[9] < '0' || text[9] > '9')
            {
                throw new FormatException();
            }
            return (text[0] - '0') * 1000000000 +
                (text[1] - '0') * 100000000 +
                (text[2] - '0') * 10000000 +
                (text[3] - '0') * 1000000 +
                (text[4] - '0') * 100000 +
                (text[5] - '0') * 10000 +
                (text[6] - '0') * 1000 +
                (text[7] - '0') * 100 +
                (text[8] - '0') * 10 +
                (text[9] - '0');
        }
    }

    class Program
    {
        [STAThreadAttribute]
        static void Main(string[] args)
        {
            Random rnd = new Random(Environment.TickCount);
            string[] list = new string[10000];//生成10000个测试数据
            int[] myparse = new int[10000];
            int[] sysparse = new int[10000];
            for (int i = 0; i < 10000; i++) list[i] = rnd.Next(0, int.MaxValue).ToString();
            //MyParse
            int tick1 = Environment.TickCount;
            for (int i = 0; i < 1000; i++)
            {
                for (int j = 0; j < 10000; j++)
                {
                    myparse[j] = list[j].MyParse();
                }
            }
            tick1 = Environment.TickCount - tick1;
            int tick2 = Environment.TickCount;
            for (int i = 0; i < 1000; i++)
            {
                for (int j = 0; j < 10000; j++)
                {
                    sysparse[j] = int.Parse(list[j]);
                    //int.TryParse(list[j], out sysparse[j]);
                }
            }
            tick2 = Environment.TickCount - tick2;
            Console.WriteLine("MyParse:" + tick1.ToString());
            Console.WriteLine("int.Parse:" + tick2.ToString());
            Console.ReadKey();
        }
    }
}

运行结果

MyParse:3986
int.Parse:5157