title: How to change extension of string path in C#?
body: <p>Below is my string value</p>
  
  <pre><code>string strFile = @"http://login.com/Uploads/g05fgxeto4dvsf5531yb3l45_16_8_2011_1_25_37.doc";
  </code></pre>
  
  <p>And I need to replace this file path value by </p>
  
  <pre><code>http://login.com/Uploads/g05fgxeto4dvsf5531yb3l45_16_8_2011_1_25_37.pdf
  </code></pre>
  
  <p>Thanks.</p>