WPF TouchDown事件延迟

Question

很简单，我在WPF4中的UserControl上接收TouchDown事件时遇到了令人无法接受的延迟。我对事件堆栈的理解是，PreviewTouchDown首先被发送但它仍然需要大约300ms-500ms。代码如下。

<UserControl x:Class="MyButton"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" 
         d:DesignHeight="300" 
         d:DesignWidth="300" 
         Stylus.IsPressAndHoldEnabled="False"
         PreviewTouchDown="ProcessPreviewTouchDown"
         PreviewTouchUp="ProcessPreviewTouchUp">
</UserControl>

我还在窗口代码中添加了以下内容：

num = GlobalAddAtom(atom);
if (num == 0L)
{
   return false;
}
if (enable)
{
   return (RemoveProp(hWnd, atom).ToInt64() == 1L);
}
else
{
   int TABLET_DISABLE_PRESSANDHOLD        = 0x00000001;
   int TABLET_DISABLE_PENTAPFEEDBACK      = 0x00000008;
   int TABLET_DISABLE_PENBARRELFEEDBACK   = 0x00000010;
   int TABLET_DISABLE_TOUCHUIFORCEOFF     = 0x00000200;
   int TABLET_DISABLE_FLICKS              = 0x00010000;

   int dwHwndTabletProperty = 0x1010019 |
                    TABLET_DISABLE_PRESSANDHOLD |
                    TABLET_DISABLE_PENTAPFEEDBACK | 
                    TABLET_DISABLE_TOUCHUIFORCEOFF |
                    TABLET_DISABLE_PENBARRELFEEDBACK |
                    TABLET_DISABLE_FLICKS;

   return (SetProp(hWnd, atom, new IntPtr(dwHwndTabletProperty)) == 1);
}

这肯定会删除UI，但导致没有可见的速度增加（即使应该使用TABLET_DISABLE_PRESSANDHOLD，但我怀疑这与将Stylus.IsPressAndHoldEnabled="False"添加到XAML相同）。

如果有人对如何使这种延迟消失有任何指示，我将非常感激。