正则表达式的一个简单例子

/**//*




csc /r:System.Text.RegularExpressions.dll,System.dll Validation.cs




*/






using System.Text.RegularExpressions;


using System;






class Validation




...{


public static void Main()




...{


String strToTest;


Validation objValidate=new Validation();




Console.Write("Enter a String to Test for Alphabets:");


strToTest=Console.ReadLine();


if(objValidate.IsAlpha(strToTest))




...{


Console.WriteLine("{0} is Valid Alpha String",strToTest);


}


else




...{


Console.WriteLine("{0} is not a Valid Alpha String",strToTest);


}


}




// Function to test for Positive Integers.




public bool IsNaturalNumber(String strNumber)




...{


Regex objNotNaturalPattern=new Regex("[^0-9]");


Regex objNaturalPattern=new Regex("0*[1-9][0-9]*");




return !objNotNaturalPattern.IsMatch(strNumber) &&


objNaturalPattern.IsMatch(strNumber);


}




// Function to test for Positive Integers with zero inclusive




public bool IsWholeNumber(String strNumber)




...{


Regex objNotWholePattern=new Regex("[^0-9]");




return !objNotWholePattern.IsMatch(strNumber);


}




// Function to Test for Integers both Positive & Negative




public bool IsInteger(String strNumber)




...{


Regex objNotIntPattern=new Regex("[^0-9-]");


Regex objIntPattern=new Regex("^-[0-9]+$|^[0-9]+$");




return !objNotIntPattern.IsMatch(strNumber) &&


objIntPattern.IsMatch(strNumber);


}




// Function to Test for Positive Number both Integer & Real




public bool IsPositiveNumber(String strNumber)




...{


Regex objNotPositivePattern=new Regex("[^0-9.]");


Regex objPositivePattern=new Regex("^[.][0-9]+$|[0-9]*[.]*[0-9]+$");


Regex objTwoDotPattern=new Regex("[0-9]*[.][0-9]*[.][0-9]*");




return !objNotPositivePattern.IsMatch(strNumber) &&


objPositivePattern.IsMatch(strNumber) &&


!objTwoDotPattern.IsMatch(strNumber);


}




// Function to test whether the string is valid number or not


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);


}




// Function To test for Alphabets.




public bool IsAlpha(String strToCheck)




...{


Regex objAlphaPattern=new Regex("[^a-zA-Z]");




return !objAlphaPattern.IsMatch(strToCheck);


}




// Function to Check for AlphaNumeric.




public bool IsAlphaNumeric(String strToCheck)




...{


Regex objAlphaNumericPattern=new Regex("[^a-zA-Z0-9]");




return !objAlphaNumericPattern.IsMatch(strToCheck);


}






}