using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^\d+\.\s*ABC[^\S\n]*(?:\n.+)*";
string input = @"1. Hello world
1.1 bla bla bla
1.2 more bla bla
1.3 even more bla bla ABC
2. ABC
2.1 hello ABC
2.2 bla bla bla
3. XYZ
3.1 bla bla
3.2 more bla bla
3.3 even more bla bla
1. Hello world
1.1 bla bla bla
1.2 more bla bla
1.3 even more bla bla ABC
2. XYZ
2.1 bla bla
2.2 more bla bla
2.3 even more bla bla
3. MNO
3.1 hello MNO
3.2 bla bla bla
4. ABC
4.1 hello ABC
4.2 bla bla bla";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx