public void SetText(string text, double yPositionAsPercentage)
{
txtPreview.Text = text;
var info = new Scrollbarinfo();
info.CbSize = Marshal.SizeOf(info);
GetScrollBarInfo(txtPreview.Handle, OBJID_HSCROLL, ref info);
//Position the scrollbar based on the presentage
GetScrollRange(txtPreview.Handle, SB_HORZ, out int _, out int vSmaxPos);
var tumbSize = info.XyThumbBottom - info.XyThumbTop;
var pos = (int)Math.Floor(vSmaxPos * yPositionAsPercentage);
pos -= tumbSize / 2;
if (pos < 0)
{
pos = 0;
}
SetScrollPos(txtPreview.Handle, SB_HORZ, pos, true);
PostMessageA(txtPreview.Handle, WM_HSCROLL, SB_THUMBPOSITION + 0x10000 * pos, 0);
_isActive = true;
}
private static extern int GetScrollBarInfo(IntPtr hWnd, uint idObject, ref Scrollbarinfo psbi);
public static extern bool GetScrollBarInfo([In] IntPtr a_hwnd, int a_idObject, ref Scrollbarinfo a_psbi);