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How to: Use Regular Expressions to Search and Replace Text Strings

The SubDocument.ReplaceAll method allows you to search and replace specific text strings using Regular Expressions.

This example shows how to use this method to change US formatted dates (moth/day/year) in the document to European format (year-month-day and day.month.year).

Document document = richEditDocumentServer1.Document;
document.AppendText("12\\14\\2014" + Environment.NewLine);
string pattern = @"(?<mm>\d{2}).(?<dd>\d{2}).(?<yyyy>\d{4})";
string replacementString = @"${yyyy}-${mm}-${dd} or ${dd}.${mm}.${yyyy}";
System.Text.RegularExpressions.Regex myRegEx = new System.Text.RegularExpressions.Regex(pattern);
int count = document.ReplaceAll(myRegEx, replacementString);
System.Windows.Forms.MessageBox.Show(String.Format("We've done {0} replacement(s).", count));