Simple RegEx replace in C#

Feb 01, 2007

As I don’t use regular expressions that often I always forget the syntax. So I thought I just put a basic replace pattern up here.

This method takes a schema, finds all places where is says schemaLocation=”whatever” in a text and changes this to schemaLocation=”whatever.xsd“ and then returns the schema.

<div><span style="color: #0000FF; ">private</span><span style="color: #000000; "> XmlSchema FixSchemaLocation(XmlSchema schema)
{
  System.Text.RegularExpressions.Regex locationReplacePattern </span><span style="color: #000000; ">=</span><span style="color: #000000; "> </span><span style="color: #0000FF; ">new</span><span style="color: #000000; "> System.Text.RegularExpressions.Regex(</span><span style="color: #000000; ">"</span><span style="color: #000000; ">schemaLocation=\"(?<location>.*?)\"</span><span style="color: #000000; ">"</span><span style="color: #000000; ">);
  </span><span style="color: #0000FF; ">string</span><span style="color: #000000; "> locationReplaceValue </span><span style="color: #000000; ">=</span><span style="color: #000000; "> </span><span style="color: #000000; ">"</span><span style="color: #000000; ">schemaLocation=\"${location}.xsd\"</span><span style="color: #000000; ">"</span><span style="color: #000000; ">;
  </span><span style="color: #008000; ">//</span><span style="color: #008000; ">Puts .xsd after the schemaLocation. We need this find the imported schemas</span><span style="color: #008000; ">
</span><span style="color: #000000; ">  StringWriter sw </span><span style="color: #000000; ">=</span><span style="color: #000000; "> </span><span style="color: #0000FF; ">new</span><span style="color: #000000; "> StringWriter();
  schema.Write(sw);
  XmlSchema formatedSchema </span><span style="color: #000000; ">=</span><span style="color: #000000; "> XmlSchema.Read(</span><span style="color: #0000FF; ">new</span><span style="color: #000000; "> StringReader(locationReplacePattern.Replace(sw.ToString(), locationReplaceValue)),</span><span style="color: #0000FF; ">null</span><span style="color: #000000; ">);
  </span><span style="color: #0000FF; ">return</span><span style="color: #000000; "> formatedSchema;
}</span></div>