winapi - Windows 10 中的 Win32 工具提示灰线错误

Question

自 Windows XP 时代以来，我们多年来一直在使用旧版 VB6 组件中创建经典 Win32 多行工具提示的代码。它在除 Windows 10 之外的所有最新版本的 MS Windows(7、8.1)中运行良好。此操作系统的工具提示中会出现一条寄生水平灰线。此问题的最佳演示是包含多行文本的工具提示窗口(主要提示文本是多行和/或工具提示具有粗体标题):

正确的工具提示应如下所示(Windows 8.1 的屏幕):

下面是当工具提示窗口没有图 block /图标但仅包含多行文本时同一问题的另一个示例:

这条寄生灰线也出现在单行工具提示中 - 尽管乍一看并不明显:

可能是什么？这是 Windows 10 中的错误，还是工具提示 API 中发生了某些变化？

<小时/>

下面是用于初始化工具提示的方法的代码:

Public Function Create(ByVal ParentHwnd As Long) As Boolean
   Dim lWinStyle As Long

   If m_lTTHwnd <> 0 Then
      DestroyWindow m_lTTHwnd
   End If

   m_lParentHwnd = ParentHwnd

   lWinStyle = TTS_ALWAYSTIP Or TTS_NOPREFIX

   m_lTTHwnd = CreateWindowExA(0&, _
      TOOLTIPS_CLASS, _
      vbNullString, _
      lWinStyle, _
      CW_USEDEFAULT, _
      CW_USEDEFAULT, _
      CW_USEDEFAULT, _
      CW_USEDEFAULT, _
      0&, _
      0&, _
      App.hInstance, _
      0&)

   'now set our tooltip info structure
   Dim tiA As TOOLINFOA
   Dim tiW As TOOLINFOW
   If g_bIsNt Then
      With tiW
         .lSize = Len(tiW)
         .lFlags = TTF_SUBCLASS Or TTF_IDISHWND
         .hWnd = m_lParentHwnd
         .lId = m_lParentHwnd '0
         .hInstance = App.hInstance
         .lpStr = StrPtr(mvarTipText)
      End With
   Else
      With tiA
         .lSize = Len(tiA)
         .lFlags = TTF_SUBCLASS Or TTF_IDISHWND
         .hWnd = m_lParentHwnd
         .lId = m_lParentHwnd
         .hInstance = App.hInstance
         .lpStr = mvarTipText
      End With
   End If

   'add the tooltip structure
   If g_bIsNt Then
      SendMessage m_lTTHwnd, TTM_ADDTOOLW, 0&, tiW
   Else
      SendMessage m_lTTHwnd, TTM_ADDTOOLA, 0&, tiA
   End If

   'if we want a title or we want an icon
   If mvarTitle <> vbNullString Or mvarIcon <> igToolTipIconNone Then
      If g_bIsNt Then
         SendMessage m_lTTHwnd, TTM_SETTITLEW, mvarIcon, ByVal StrPtr(mvarTitle)
      Else
         SendMessage m_lTTHwnd, TTM_SETTITLEA, mvarIcon, ByVal mvarTitle
      End If
   End If

   ' set the time parameters
   SendMessageByLongA m_lTTHwnd, TTM_SETDELAYTIME, TTDT_AUTOPOP, mvarVisibleTime
   SendMessageByLongA m_lTTHwnd, TTM_SETDELAYTIME, TTDT_INITIAL, mvarDelayTime

   'according to MSDN, we should set TTM_SETMAXTIPWIDTH to a positive value
   'to enable multiline tooltips
   SendMessageByLongA m_lTTHwnd, TTM_SETMAXTIPWIDTH, 0, 100000
End Function

Answer 1

为了解决这个问题，我们不应该设置TOOLINFO结构的hwnd字段。相应的代码部分应如下所示:

'now set our tooltip info structure
Dim tiA As TOOLINFOA
Dim tiW As TOOLINFOW
If g_bIsNt Then
   With tiW
      .lSize = Len(tiW)
      .lFlags = TTF_SUBCLASS Or TTF_IDISHWND
      .lId = m_lParentHwnd
      .hInstance = App.hInstance
      .lpStr = StrPtr(mvarTipText)
   End With
Else
   With tiA
      .lSize = Len(tiA)
      .lFlags = TTF_SUBCLASS Or TTF_IDISHWND
      .lId = m_lParentHwnd
      .hInstance = App.hInstance
      .lpStr = mvarTipText
   End With
End If