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

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

enum DWMWINDOWATTRIBUTE : uint

Enum DWMWINDOWATTRIBUTE