C#判断一个string是否为数字

方案二：正则表达式(推荐)
using System.Text.RegularExpressions;
a)
public static bool IsNumeric(string value)
{
         return Regex.IsMatch(value, @"^[+-]?\d*[.]?\d*$");
}
public static bool IsInt(string value)
{
         return Regex.IsMatch(value, @"^[+-]?\d*$");
}
public static bool IsUnsign(string value)
{
         return Regex.IsMatch(value, @"^\d*[.]?\d*$");
}

 public static bool isTel(string strInput)
{
        return Regex.IsMatch(strInput, @"\d{3}-\d{8}|\d{4}-\d{7}");
}

b)

using System;
using System.Text.RegularExpressions;

public bool IsNumber(String strNumber)
{
           Regex objNotNumberPattern=new Regex("[^0-9.-]");
           Regex objTwoDotPattern=new Regex("[0-9]*[.][0-9]*[.][0-9]*");
           Regex objTwoMinusPattern=new Regex("[0-9]*[-][0-9]*[-][0-9]*");
           String strValidRealPattern="^([-]|[.]|[-.]|[0-9])[0-9]*[.]*[0-9]+$";
           String