using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"<item>[\s\S]*?<sub>(.*?)<\/sub>((?!<sub>)[\s\S])*<\/item>";
string input = @"<item> fffffffffffff
<sub>aaaa</sub>
<value>111</value>
</item>
<item>
<sub>eeee</sub> arg34ddddddddddddddd
<atag>ddd</atag>
<sub>aaaa</sub>
<value>222</value>
</item>
<item>
<sub>eeee</sub> arg34ddddddddddddddd
<atag>ddd</atag>
<sub>aaaa</sub>
</item>";
foreach (Match m in Regex.Matches(input, pattern))
{
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