title: Slice a string in two or more parts in c#
body: <p>I have a string like this (c#, winforms):</p>
  
  <pre><code>private string source = @"CDM_DEBUG\D1_XS1000psc_1"
  </code></pre>
  
  <p>I want to have this string in two parts, first part should be everything before the last underscore that will be 'CDM_DEBUG\D1_XS1000psc' and second part should be '_1'.</p>
  
  <p>Then I want to make a new string from the first part and make it to 'CDM_DEBUG\D1_XS1000psc_2'</p>
  
  <p>what is the fastest way of doing this?</p>