//Create a new LayoutIterator object
LayoutIterator iterator = new LayoutIterator(richEditControl1.DocumentLayout);
int documentRows = 0;

    //Call the MoveNext method with the passed LayoutLevel.Row value
    //to process page lines:
    while (iterator.MoveNext(LayoutLevel.Row))
    {
       //Count visited lines until the method returns false
       documentRows++;
    }

//Show the result number in the message box
MessageBox.Show(String.Format("The document contains {0} lines", documentRows));

'Create a new LayoutIterator object
Dim [iterator] As New LayoutIterator(richEditControl1.DocumentLayout)

'Call the MoveNext method with the passed LayoutLevel.Row value
'to process page lines:
Dim documentRows As Integer = 0
      Do While [iterator].MoveNext(LayoutLevel.Row)
            documentRows += 1
       Loop
'Show the result number in the message box:
MessageBox.Show(String.Format("The document contains {0} lines", documentRows))

int rowCount = 0;
int pageCount = richEditControl1.DocumentLayout.GetPageCount();

//Create a new <b>Visitor</b> object for every document page
for (int i = 0; i < pageCount; i++)
 {
   MyLayoutVisitor visitor = new MyLayoutVisitor(); 

   //Call the Visit method for the current layout page and count its lines
   visitor.Visit(richEditControl1.DocumentLayout.GetPage(i));
   rowCount += visitor.DocumentRows;
 }

//Show the result in the message box 
MessageBox.Show(String.Format("The document contains {0} lines", rowCount));

//Create a LayoutVisitor class descendant: 
public class MyLayoutVisitor : LayoutVisitor
{
  public int DocumentRows = 0;

  //Override the <b>VisitRow</b> method to count lines 
  //located only in main document body,
  //i.e. lines located on the LayoutPageArea level
   protected override void VisitRow(LayoutRow row)
   {
     if (row.GetParentByType<LayoutPageArea>() != null)
     {
       DocumentRows++;
       base.VisitRow(row);
     }
   }
}

Dim rowCount As Integer = 0
Dim pageCount As Integer = richEditControl1.DocumentLayout.GetPageCount()

'Create a new Visitor object for every document page
For i As Integer = 0 To pageCount - 1
  Dim visitor As MyLayoutVisitor = New MyLayoutVisitor()

  'Call the Visit method for the current layout page and count its lines
  visitor.Visit(richEditControl1.DocumentLayout.GetPage(i))
  rowCount += visitor.DocumentRows
   Next
'Show the result in the message box 
MessageBox.Show(String.Format("The document contains {0} lines", rowCount))

'Create a LayoutVisitor class descendant:
Public Class MyLayoutVisitor
    Inherits LayoutVisitor

    Public DocumentRows As Integer = 0
    'Override the VisitRow method to count lines 
    'located only in main document body,
    'i.e. lines located on the LayoutPageArea level
    Protected Overrides Sub VisitRow(ByVal row As LayoutRow)
        If row.GetParentByType(Of LayoutPageArea)() IsNot Nothing Then
            DocumentRows += 1
            MyBase.VisitRow(row)
        End If
    End Sub
End Class