方案一：TryCatch(执行效率不高)
private bool IsNumberic(string oText)
{
try
{
int var1=Convert.ToInt32 (oText);
return true;
}
catch
{
return false;
}
}

方案二：正则表达式(推荐)
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]+contentquot;;
String strValidIntegerPattern="^([-]|[0-9])[0-9]*contentquot;;
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*contentquot;);
}
public static bool IsInt(string value)
{
return Regex.IsMatch(value, @"^[+-]?\d*contentquot;);
}
public static bool IsUnsign(string value)
{
return Regex.IsMatch(value, @"^\d*[.]?\d*contentquot;);
}

方案三：遍历
a)
public bool isnumeric(string str)
{
char ch=new char[str.Length];
ch=str.ToCharArray();
for(int i=0;i {
if(ch[i]<48 || ch[i]>57)
return false;
}
return true;
}

b)
public bool IsInteger(string strIn) {
bool bolResult=true;
if(strIn=="") {
bolResult=false;
}
else {
foreach(char Char in strIn) {
if(char.IsNumber(Char))
continue;
else {
bolResult=false;
break;
}
}
}
return bolResult;
}

c)
public static bool isNumeric(string inString)
{
inString=inString.Trim();
bool haveNumber=false;
bool haveDot=false;
for(int i=0;i {
if (Char.IsNumber(inString[i]))
{
haveNumber=true;
}
else if(inString[i]==''.'')
{
if (haveDot)
{
return false;
}
else
{
haveDot=true;
}
}
else if(i==0)
{
if(inString[i]!=''+''&&inString[i]!=''-'')
{
return false;
}
}
else
{
return false;
}
if(i>20)
{
return false;
}
}
return haveNumber;
}

方案四：改写vb的IsNumeric源代码(执行效率不高)

//主调函数
public static bool IsNumeric(object Expression)
{
bool flag1;
IConvertible convertible1 = null;
if (Expression is IConvertible)
{
convertible1 = (IConvertible) Expression;
}
if (convertible1 == null)
{
if (Expression is char)
{
Expression = new string((char) Expression);
}
else
{
return false;
}
}
TypeCode code1 = convertible1.GetTypeCode();
if ((code1 != TypeCode.String) && (code1 != TypeCode.Char))
{
return Utils.IsNumericTypeCode(code1);
}
string text1 = convertible1.ToString(null);
try
{
long num2;
if (!StringType.IsHexOrOctValue(text1, ref num2))
{
double num1;
return DoubleType.TryParse(text1, ref num1);
}
flag1 = true;
}
catch (Exception)
{
flag1 = false;
}
return flag1;
}

//子函数
// return Utils.IsNumericTypeCode(code1);
internal static bool IsNumericTypeCode(TypeCode TypCode)
{
switch (TypCode)
{
case TypeCode.Boolean:
case TypeCode.Byte:
case TypeCode.Int16:
case TypeCode.Int32:
case TypeCode.Int64:
case TypeCode.Single:
case TypeCode.Double:
case TypeCode.Decima