DPI scaling a complete dialog box from resource - winapi

Question

I setup per-monitor DPI scaling in a Win32 app, and my part works fine, however opening up a dialog box created in the resource editor doesn't scale itself (I would think using dialog units, it would).
Is there a way to scale everything from a dialog resource and be compatible with, say, Win8.1, as well as Win10, and even Win7?

Answer 1

Per-Monitor and Per-Monitor (V2) DPI Awareness:
It is recommended that desktop applications be updated to use
per-monitor DPI awareness mode, allowing them to immediately render
correctly whenever the DPI changes. When an application reports to
Windows that it wants to run in this mode, Windows will not bitmap
stretch the application when the DPI changes, instead sending
WM_DPICHANGED to the application window. It is then the complete
responsibility of the application to handle resizing itself for the
new DPI. Most UI frameworks used by desktop applications (Windows
common controls (comctl32), Windows Forms, Windows Presentation
Framework, etc.) do not support automatic DPI scaling, requiring
developers to resize and reposition the contents of their windows
themselves.
You can resize the dialog box in the WM_DPICHANGED message.
case WM_DPICHANGED:
{
LPRECT lpRect = (LPRECT)lParam;
SetWindowPos(hWnd, nullptr, lpRect->left, lpRect->top, lpRect->right - lpRect->left, lpRect->bottom - lpRect->top, SWP_NOZORDER | SWP_NOACTIVATE);
return 0;
}
Updated:
For per-monitor DPI, v2 is the only one that can handle the dialog DPI scale., v1 does not so on WIndows 8.1 and older versions of Window 10, it has to be done manually. Windows 8.1 and older Windows 10, we don't scale controls. So the solution should be just resize the dialog. It has to enumerate all controls and resize them during WM_DPICHANGED if the dialog is not resizable.