static unsafe extern int DwmGetWindowAttribute(IntPtr hWnd, DwmWindowAttribute dwAttribute, void* pvAttribute, int cbAttribute);

    public enum DwmWindowAttribute {

public static extern int DwmSetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE attr, ref int attrValue, int attrSize);

Public Shared Function DwmSetWindowAttribute(hwnd As IntPtr, attr As DWMWINDOWATTRIBUTE, ByRef attrValue As Integer, attrSize As Integer) As Integer

DWMWINDOWATTRIBUTE

https://docs.microsoft.com/en-us/windows/win32/api/dwmapi/ne-dwmapi-dwmwindowattribute

enum DwmWindowAttribute : uint

Enum DWMWINDOWATTRIBUTE

static extern int DwmGetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE dwAttribute, out bool pvAttribute, int cbAttribute);

static extern int DwmGetWindowAttribute(IntPtr hwnd, DWMWINDOWATTRIBUTE dwAttribute, out RECT pvAttribute, int cbAttribute);

DWMWINDOWATTRIBUTE, RECT