IWin32Window只需要一个Handle属性,这不是很难实现,因为你已经有了IntPtr.实现IWin32Window的Create a wrapper类：

public class WindowWrapper : System.Windows.Forms.IWin32Window
{
    public WindowWrapper(IntPtr handle)
    {
        _hwnd = handle;
    }

    public WindowWrapper(Window window)
    {
        _hwnd = new WindowInteropHelper(window).Handle;
    }

    public IntPtr Handle
    {
        get { return _hwnd; }
    }

    private IntPtr _hwnd;
}

你会得到你的IWin32Window这样：

IWin32Window win32Window = new WindowWrapper(new WindowInteropHelper(this).Handle);

或(作为回应KeithS的建议)：

IWin32Window win32Window = new WindowWrapper(this);

选项2(thx to Scott Chamberlain的评论)

使用现有的NativeWindow类,它实现了IWin32Window：

IWin32Window win32Window = new NativeWindow(); 
win32Window.AssignHandle(new WindowInteropHelper(this).Handle);