在WPF WebBrowser

Question

我尝试根据Microsoft提供here的说明启用DPI支持。我正在使用WPF WebBrowser控件：

<Grid>
    <WebBrowser Name="BrowserPane"
                Source="pack://siteoforigin:,,,/Resources/HTML/index.html"
                HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                LoadCompleted="BrowserPane_LoadCompleted"/>
</Grid>

我的代码实现了IDocHostUIHandler，如下所示：

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.ShowContextMenu([In, MarshalAs(UnmanagedType.U4)] uint dwID, [In] Native.POINT pt, [In, MarshalAs(UnmanagedType.Interface)] object pcmdtReserved, [In, MarshalAs(UnmanagedType.Interface)] object pdispReserved)
    {
        return S_OK;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.GetHostInfo([In, Out] Native.DOCHOSTUIINFO info)
    {
        info.dwFlags = (uint)Native.DOCHOSTUIFLAG.DPI_AWARE;
        info.dwDoubleClick = 0;
        return S_OK;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.ShowUI([In, MarshalAs(UnmanagedType.U4)] uint dwID, [In, MarshalAs(UnmanagedType.Interface)] object activeObject, [In, MarshalAs(UnmanagedType.Interface)] object commandTarget, [In, MarshalAs(UnmanagedType.Interface)] object frame, [In, MarshalAs(UnmanagedType.Interface)] object doc)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.HideUI()
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.UpdateUI()
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.EnableModeless([In, MarshalAs(UnmanagedType.Bool)] bool fEnable)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.OnDocWindowActivate([In, MarshalAs(UnmanagedType.Bool)] bool fActivate)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.OnFrameWindowActivate([In, MarshalAs(UnmanagedType.Bool)] bool fActivate)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.ResizeBorder([In] Native.COMRECT rect, [In, MarshalAs(UnmanagedType.Interface)] object doc, [In, MarshalAs(UnmanagedType.Bool)] bool fFrameWindow)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.TranslateAccelerator([In] ref MSG msg, [In] ref Guid group, [In, MarshalAs(UnmanagedType.U4)] uint nCmdID)
    {
        return S_FALSE;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.GetOptionKeyPath([MarshalAs(UnmanagedType.LPArray), Out] string[] pbstrKey, [In, MarshalAs(UnmanagedType.U4)] uint dw)
    {
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.GetDropTarget([In, MarshalAs(UnmanagedType.Interface)] object pDropTarget, [MarshalAs(UnmanagedType.Interface), Out] out object ppDropTarget)
    {
        ppDropTarget = null;
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.GetExternal([MarshalAs(UnmanagedType.IDispatch), Out] out object ppDispatch)
    {
        ppDispatch = this.Browser.ObjectForScripting;
        return S_OK;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.TranslateUrl([In, MarshalAs(UnmanagedType.U4)] uint dwTranslate, [In, MarshalAs(UnmanagedType.LPWStr)] string strURLIn, [MarshalAs(UnmanagedType.LPWStr), Out] out string pstrURLOut)
    {
        pstrURLOut = null;
        return E_NOTIMPL;
    }

    [return: MarshalAs(UnmanagedType.U4)]
    uint Native.IDocHostUIHandler.FilterDataObject([In] IDataObject pDO, [Out] out IDataObject ppDORet)
    {
        ppDORet = null;
        return E_NOTIMPL;
    }

我在WebBrowser.LoadCompleted事件中设置处理程序，如下所示：

    var doc = this.Browser.Document as Native.ICustomDoc;
    if (doc != null)
        doc.SetUIHandler(this);

IDocHostUIHandler上的一些方法被调用。例如ShowContextMenu成功禁用上下文菜单。但GetHostInfo从未被调用过。我是否设置了UI处理程序太晚了？

编辑：已经观察到此代码适用于某些Win10机器，但不适用于MY Win10机器。我的机器上还有其他东西需要配置才能使用吗？