ts4dotnet.5.cs

var nonRenderingCategories = new UnicodeCategory[] {
UnicodeCategory.Control,
UnicodeCategory.OtherNotAssigned,
UnicodeCategory.Format,
UnicodeCategory.Surrogate };
using StreamReader sr = new StreamReader(dotnetFile);
while (sr.Peek() >= 0)
{
  var c = (char)sr.Read();
  var category = Char.GetUnicodeCategory(c);
  var isPrintable = Char.IsWhiteSpace(c) ||
    !nonRenderingCategories.Contains(category);
  if (!isPrintable
  {
    alert(dotnetFile);
    issuesCount++;
    break;     
    }
  }  
sr.Close();
sr.Dispose();