Rotating text in VB.NET

Q:
I am currently writing a vb.net project using your pdfnet control.

I'm trying to put a piece of rotated text on a pdf page, but I can't
get it working. In your manual, this piece is missing and the c# code
on an example page didn't do it for me.

Is it possible to give me a vb.net example to do this, or just a draft
of this part of the manual or something that will get me further?
------------
A:

To rotate text you can try the following:

Dim mtx As Matrix2D = elem.GetTextMatrix()

' Rotate 90 deg
double deg2rad = 3.1415926535 / 180.0;
Dim rot As Matrix2D = New Matrix2D.RotationMatrix( 90 * deg2rad ))
mtx.Concat(rot.m_a, rot.m_b, rot.m_c, rot.m_d, rot.m_h, rot.m_v);

elem.SetTextMatrix(mtx)

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There is some information related to matrix manipulation in PDFNet API
Reference: