using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Drawing; namespace RegularExpressionConsoleApplication
{
class Program
{
static void Main(string[] args)
{
//LoopBackMatch(); //回溯匹配(涉及子運算式)
//LoopForwardMatch(); //向前匹配(?=)
//LoopAfterwardMatch(); //向後匹配(?<=)
//LoopForwardAndAfterwardMatch(); //向前向後匹配結合
ConditionItems(); //嵌入條件之回溯匹配
} /// <summary>
/// 向前匹配
/// </summary>
static void LoopForwardMatch()
{
string text = " http://www.cnblogs.com";
string expression = @".+(?=:)";
Regex reg = new Regex(expression, RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(text);
foreach (Match match in mc)
{
Console.WriteLine(match.Value);
} Console.ReadKey();
} /// <summary>
/// 向後匹配
/// </summary>
static void LoopAfterwardMatch()
{
string text = "ABC01: $12.56";
string expression = @"(?<=$)[0-9.]+";
Regex reg = new Regex(expression, RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(text);
foreach (Match match in mc)
{
Console.WriteLine(match.Value);
} Console.ReadKey();
} /// <summary>
/// 向前向後匹配結合
/// </summary>
static void LoopForwardAndAfterwardMatch()
{
StringBuilder sbStr = new StringBuilder();
sbStr.Append("<Head>");
sbStr.Append("rn ");
sbStr.Append("<Title>Ben Forta's HomePage</Title>");
sbStr.Append("rn");
sbStr.Append("</Head>"); string expression = @"(?<=<title>).*?(?=</title>)";
Regex reg = new Regex(expression, RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(sbStr.ToString());
foreach (Match match in mc)
{
Console.WriteLine(match.Value);
}
Console.ReadKey();
} /// <summary>
/// 注意，這裡利用了回溯匹配法
/// </summary>
/// <param name="args"></param>
static void LoopBackMatch()
{
string text = " this is is a text, and I want to know know if there is any repeated words in it.";
string expression = @"[ ]+(w+)[ ]+1";
Regex reg = new Regex(expression, RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(text);
foreach (Match match in mc)
{
Console.WriteLine(match.Value);
} Console.ReadKey();
} /// <summary>
/// 嵌入條件,待匹配文本如下:
/*********************************************************
* <!-- Nav Bar -->
* <TD>
* <a href='/home'><img src='/images/home.gif'></a>
* <img src=/images/spacer.gif'>
* <a href='/search'><img src='/images/search.gif'></a>
* <img src='/images/spacer.gif'>
* <a href='/help'><img src='/images/help.gif'></a>
* </td>
*********************************************************/
/// </summary>
static void ConditionItems()
{
StringBuilder text = new StringBuilder();
text.Append("<!-- Nav Bar -->");
text.Append("rn");
text.Append("<TD>");
text.Append("rn");
text.Append("<a href='/home'><img src='/images/home.gif'></a>");
text.Append("rn");
text.Append("<img src=/images/spacer.gif'>");
text.Append("rn");
text.Append("<a href='/search'><img src='/images/search.gif'></a>");
text.Append("rn");
text.Append("<img src='/images/spacer.gif'>");
text.Append("rn");
text.Append("<a href='/help'><img src='/images/help.gif'></a>");
text.Append("rn");
text.Append("</td>"); string expression = @"(<as+[^>]+>s*)?<imgs+[^>]+>(?(1)s*</a>)";
Regex reg = new Regex(expression, RegexOptions.IgnoreCase);
MatchCollection mc = reg.Matches(text.ToString());
//foreach (Match match in mc)
//{
// Console.WriteLine(match.Value);
//} Console.ForegroundColor = ConsoleColor.Yellow;
Console.WriteLine("the total count of match result is: " + mc.Count);
for (int i = 0; i < mc.Count; i++)
{
Match match = mc[i]; Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("|-Match["+i+"] is :"+match.Value);
GroupCollection groups = match.Groups;
for (int j = 0; j < groups.Count; j++)
{
Console.ForegroundColor = ConsoleColor.DarkGreen; Console.WriteLine("|---Groups[" + j + "] is :" + groups[j]);
}
}
Console.ReadKey();
}
}
} |
