title: StringReader.ReadLine clears the given string, is there chance to not clean the string?
body: <p>When I am using StringReader.ReadLine to read text from array of strings, it reads it perfectly but it also clears my array, </p>
  
  <pre><code>using (StringReader reader = new StringReader(filesGroupList[x]))
         {
            while ((filesGroupList[x] = reader.ReadLine()) != null)
               {
                  ...
               }
          }
  </code></pre>
  
  <p>Now, filesGroupList is empty. So if i will want to read data from this string again it will give me null reference exception, so the only way for me is to create a copy of this array before using ReadLine, but is there chance to avoid it? so when StringReaded finished reading the line, my line still stays inside array.</p>