using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^[\d\/ :]+:[^:]+:(.*)$|(.*)$";
string substitution = @"$1$2";
string input = @"11/04/2015 11:45:01: James: Cheers guys, enjoy the weekend!
11/04/2015 12:08:55: Sarah: Sounds good James
11/04/2015 12:09:24: Sarah: What are the details of the trip?
11/04/2015 12:19:06: Leah: Driving up on Friday.
Saturday we'll hit the beach.
Sunday paaaaarty!
11/04/2015 12:29:54: James: Nice.";
RegexOptions options = RegexOptions.Multiline;
Regex regex = new Regex(pattern, options);
string result = regex.Replace(input, substitution);
}
}
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