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  • C#正则表达式应用范例

    The following example shows the use of Regular Expresssions in C#.This program has basic validation scripts for validation easily useable in all programs.


    /*

    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);
    }


    }


    There is another simple way to perform these validation think of it while the next article comes.
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  • 原文地址:https://www.cnblogs.com/springxie/p/1356157.html
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