How to have themed tabs for all alignments in the WinForms TabControlAdv?

Alignment

Themed tabs alignments are implemented in v.4.1 You could set Themes Enabled to true and set Alignments to Top, Bottom, Left, Right. Set RotateTabsWhenVertical property to true to make the tab's text horizontal when they are aligned to top or bottom.

For earlier versions, due to a shortcoming in the .NET framework it is not possible to draw themed tabs for all alignments. The themed tabs are supported on the top only, and hence for all other alignments we silently turn off the themes. However, the trick to achieve this feature is to first draw the themed tab to a bitmap and then RotateFlip the bitmap to the required orientation. Now you just draw the bitmap onto the provided Graphics object as usual. Please refer to the test sample attached below that illustrates this technique.

Reference link: https://help.syncfusion.com/windowsforms/tabcontrol/alignment