Several months back, I wrote about how to determine whether or not a device supported screen rotation.  This post prompted the question of how to programmatically rotate the device..

The snippets below check the device's current display orientation.  If portrait (Angle0), the orientation is changed to landscape (Angle90).  If the device has any orientation other than Angle0, it is changed to portrait. 

C#
//---------------------------------------------------------------------
//THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
//KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//PARTICULAR PURPOSE.
//---------------------------------------------------------------------
using System;
using Microsoft.WindowsCE.Forms;

class Program
{
    static void Main()
    {
        if(SystemSettings.ScreenOrientation == ScreenOrientation.Angle0)
        {
            // if portrait, change to landscape
            SystemSettings.ScreenOrientation = ScreenOrientation.Angle90;
        }
        else
        {
            // change to portrait
            SystemSettings.ScreenOrientation = ScreenOrientation.Angle0;
        }
    }
}

VB
'---------------------------------------------------------------------
'THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
'KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
'IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
'PARTICULAR PURPOSE.
'---------------------------------------------------------------------
Imports Microsoft.WindowsCE.Forms
Module Module1

    Sub Main()
        If (SystemSettings.ScreenOrientation = ScreenOrientation.Angle0) Then

            ' if portrait, change to landscape
            SystemSettings.ScreenOrientation = ScreenOrientation.Angle90

        Else

            ' change to portrait
            SystemSettings.ScreenOrientation = ScreenOrientation.Angle0

        End If
    End Sub

End Module

For more information on this and other cool settings provided by the Microsoft.WindowsCE.Forms namespace, check out the MSDN documentation for SystemSettings. 

Enjoy!
--DK

Disclaimer(s):
This posting is provided "AS IS" with no warranties, and confers no rights.