高效的方法是使用正則表達式
a)
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]+$"; String strValidIntegerPattern="^([-]|[0-9])[0-9]*$"; Regex objNumberPattern =new Regex("(" + strValidRealPattern +")|(" + strValidIntegerPattern + ")"); return !objNotNumberPattern.IsMatch(strNumber) && !objTwoDotPattern.IsMatch(strNumber) && !objTwoMinusPattern.IsMatch(strNumber) && objNumberPattern.IsMatch(strNumber); }
b)
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*$"); }