How do I change the PDFViewCtrl "Structural Selection" selection color in C++?

1. I want to change the PDFViewCtrl "Structural Selection" selection
color, Please guide me how to change selection color by "Structural
Selection" .

2. How can I change the PDFViewCtrl scroll bar's appearance, for
example, foreground color, background color, or directly with the
image replacement.

Please give me ideas and gives detailed codes, thanks!

1. I want to change the PDFViewCtrl "Structural Selection" selection
color, Please guide me how to change selection color by "Structural
Selection" .

This property can't be changed in the built-in text selection tool,
however you can implement your own text selector. To select text use
pdfview.SelectTextByStruct(...)/SetlectTextByRect(...) and to obtain
the rectangles/quads for the selected text use
pdfview.GetSelection(pgnum).

2. How can I change the PDFViewCtrl scroll bar's appearance, for
example, foreground color, background color, or directly with the
image replacement.

You can disable the built-in scroll bar using
pdfview.EnableScrollbar(false) then add your own scrolls (and use Set/
GetHScrollPos, GetCanvasWidth and related methods to hook your custom
scrolls with PDFView).