title: I need a case-insensitive Replace method that works with the StringBuilder class
body: <p>I need code for a case-insensitive <code>Replace</code> method for the <code>StringBuilder</code> class. The code should work with the existing <code>StringBuilder</code>. An extension method implementation would be nice. </p>
  
  <p>Following is how I plan to use the method:</p>
  
  <pre><code>    [TestMethod]
      public void StringBuilder_Replace_TTD() {
  
          StringBuilder oRequestText = new StringBuilder(File.ReadAllText("Customer.xml"));
  
          Customer oCustomer = new Customer(null);
  
          foreach (FieldIndex iField in Enum.GetValues(typeof(FieldIndex))) {
  
              oRequestText.Replace("{" iField.ToString() + "}", oCustomer[iField]);
  
          }
  
          Debug.WriteLine(oRequestText.ToString());
      }
  </code></pre>