ABCpdf .NET PDF Component Documentation - XTransform Rotate Function. Rotate about a locked anchor point (angle in degrees).

Here we add a number of chunks of text rotated at different angles about the middle of the document.

using var doc = new Doc();
doc.FontSize = 48;
doc.TextStyle.Indent = 48;
for (int i = 1; i <= 8; i++) {
  int angle = i * 45;
  doc.Pos.String = "302 396";
  doc.Transform.Reset();
  doc.Transform.Rotate(angle, 302, 396);
  doc.AddText($"Rotated {angle}");
}
doc.Save(Server.MapPath("rotate.pdf"));

Using doc As New Doc()
  doc.FontSize = 48
  doc.TextStyle.Indent = 48
  Dim i As Integer = 1
  While i <= 8
    Dim theAngle As Integer = i * 45
    doc.Pos.String = "302 396"
    doc.Transform.Reset()
    doc.Transform.Rotate(theAngle, 302, 396)
    doc.AddText($"Rotated {theAngle}")
    System.Math.Max(System.Threading.Interlocked.Increment(i),i - 1)
  End While
  doc.Save(Server.MapPath("rotate.pdf"))
End Using