[in] Handle to a window's specified theme data. Use OpenThemeData to create an HTHEME.

If a window has a visual style applied, the GetWindowTheme function returns the most recent theme handle from OpenThemeData. If no visual style is applied, GetWindowTheme returns NULL.

public static extern IntPtr OpenThemeData(IntPtr hWnd, String classList);

Declare Function OpenThemeData Lib "uxtheme.dll" (hWnd As IntPtr, classList As String) As IntPtr

Function OpenThemeData( ByVal hwnd As IntPtr, ByVal pszClassList As String) As IntPtr