WPF'；s SafeSecurityHelper.ClientToScreen是否防止？

我的应用程序需要一个自定义版本的WPF

Thumb

控件（来自

System.Windows.Controls.Primitives

命名空间）。我发现很难自定义该控件以满足我的特殊需要，因此我正在尝试创建自己的控件，并复制/调整我在类中找到的内容

我看到thumb调用了一个内部函数：

显然，我不能在代码中使用内部类。所以我不得不怀疑，我需要它吗？看看它的来源，我不知道为什么

/// <SecurityNote>
///     Critical: This code accesses PresentationSource which is critical but does not
///     expose it.
///     TreatAsSafe: PresentationSource is not exposed and Client to Screen co-ordinates is
///     safe to expose
/// </SecurityNote>
[SecurityCritical,SecurityTreatAsSafe]
internal static Point ClientToScreen(UIElement relativeTo, Point point)
{
    GeneralTransform transform;
    PresentationSource source = PresentationSource.CriticalFromVisual(relativeTo);

    if (source == null)
    {
        return new Point(double.NaN, double.NaN);
    }
    transform = relativeTo.TransformToAncestor(source.RootVisual);
    Point ptRoot;
    transform.TryTransform(point, out ptRoot);
    Point ptClient = PointUtil.RootToClient(ptRoot, source);
    Point ptScreen = PointUtil.ClientToScreen(ptClient, source);

    return ptScreen;
}

//
///Critical：此代码访问PresentationSource，该PresentationSource是关键的，但不是关键的
///暴露它。
///治疗安全：演示源未公开，客户端与屏幕的坐标为
///安全暴露
/// 
[SecurityCritical，SecurityTreatAsSafe]
内部静态点客户端至屏幕（UIElement relativeTo，Point-Point）
{
一般变换；
PresentationSource=PresentationSource.CriticalFromVisual（relativeTo）；
if（source==null）
{
返回新点（double.NaN，double.NaN）；
}
transform=相对于TransformToAncestor（source.RootVisual）；
点根；
transform.tryttransform（point，out-ptRoot）；
Point ptClient=PointUtil.RootToClient（ptRoot，源）；
点ptScreen=PointUtil.ClientToScreen（ptClient，source）；
返回屏幕；
}

显然这里肯定有某种安全问题，但这是什么？我简单地把微软认为有必要保护的常规客户端称为屏幕有什么危险？有人知道吗

/// <SecurityNote>
///     Critical: This code accesses PresentationSource which is critical but does not
///     expose it.
///     TreatAsSafe: PresentationSource is not exposed and Client to Screen co-ordinates is
///     safe to expose
/// </SecurityNote>
[SecurityCritical,SecurityTreatAsSafe]
internal static Point ClientToScreen(UIElement relativeTo, Point point)
{
    GeneralTransform transform;
    PresentationSource source = PresentationSource.CriticalFromVisual(relativeTo);

    if (source == null)
    {
        return new Point(double.NaN, double.NaN);
    }
    transform = relativeTo.TransformToAncestor(source.RootVisual);
    Point ptRoot;
    transform.TryTransform(point, out ptRoot);
    Point ptClient = PointUtil.RootToClient(ptRoot, source);
    Point ptScreen = PointUtil.ClientToScreen(ptClient, source);

    return ptScreen;
}