Excel VBA标准MsgBox对话框使用的字体及字号是多少？

基础结论 #

VBA调用的MsgBox本质是Windows系统原生的消息框组件，它的字体和字号没有在Excel/Office层面单独定义，完全跟随系统的消息框字体配置：

• WinXP系统默认值为Tahoma 8号
• Win7及以后的Win10/Win11系统默认值为Segoe UI 9号
• 如果用户手动修改过系统外观的字体设置，该值会随用户配置变化，硬编码固定字体无法适配所有设备。

你尝试的Win32 API方向完全正确，以下是可直接运行的完整VBA实现代码，兼容32/64位Office： #

' 声明API函数
#If VBA7 Then
    Public Declare PtrSafe Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByRef lpvParam As Any, ByVal fuWinIni As Long) As Long
    Public Declare PtrSafe Function GetDC Lib "user32" (ByVal hWnd As LongPtr) As LongPtr
    Public Declare PtrSafe Function GetDeviceCaps Lib "gdi32" (ByVal hDC As LongPtr, ByVal nIndex As Long) As Long
    Public Declare PtrSafe Function ReleaseDC Lib "user32" (ByVal hWnd As LongPtr, ByVal hDC As LongPtr) As Long
#Else
    Public Declare Function SystemParametersInfo Lib "user32" Alias "SystemParametersInfoA" (ByVal uAction As Long, ByVal uParam As Long, ByRef lpvParam As Any, ByVal fuWinIni As Long) As Long
    Public Declare Function GetDC Lib "user32" (ByVal hWnd As Long) As Long
    Public Declare Function GetDeviceCaps Lib "gdi32" (ByVal hDC As Long, ByVal nIndex As Long) As Long
    Public Declare Function ReleaseDC Lib "user32" (ByVal hWnd As Long, ByVal hDC As Long) As Long
#End If

' 常量定义
Const SPI_GETNONCLIENTMETRICS As Long = &H29 ' 和十进制41完全等价，两种写法都可用
Const LOGPIXELSY As Long = 90

' LOGFONT结构定义
Private Type LOGFONT
    lfHeight As Long
    lfWidth As Long
    lfEscapement As Long
    lfOrientation As Long
    lfWeight As Long
    lfItalic As Byte
    lfUnderline As Byte
    lfStrikeOut As Byte
    lfCharSet As Byte
    lfOutPrecision As Byte
    lfClipPrecision As Byte
    lfQuality As Byte
    lfPitchAndFamily As Byte
    lfFaceName As String * 32
End Type

' NONCLIENTMETRICS结构定义
Private Type NONCLIENTMETRICS
    cbSize As Long
    iBorderWidth As Long
    iScrollWidth As Long
    iScrollHeight As Long
    iCaptionWidth As Long
    iCaptionHeight As Long
    lfCaptionFont As LOGFONT
    iSMCaptionWidth As Long
    iSMCaptionHeight As Long
    lfSMCaptionFont As LOGFONT
    iMenuWidth As Long
    iMenuHeight As Long
    lfMenuFont As LOGFONT
    lfStatusFont As LOGFONT
    lfMessageFont As LOGFONT ' 这个就是你要的消息框字体数据
End Type

' 封装好的获取消息框字体的函数，返回（字体名, 字号）的数组
Public Function GetMsgBoxFont() As Variant
    Dim ncm As NONCLIENTMETRICS
    Dim hDC As LongPtr
    Dim dpiY As Long
    Dim fontName As String
    Dim fontSize As Single
    
    ncm.cbSize = LenB(ncm)
    ' 调用API获取系统参数
    Call SystemParametersInfo(SPI_GETNONCLIENTMETRICS, LenB(ncm), ncm, 0)
    
    ' 处理字体名
    fontName = Trim(Replace(ncm.lfMessageFont.lfFaceName, Chr(0), ""))
    
    ' 计算字号
    #If VBA7 Then
        hDC = GetDC(0)
    #Else
        hDC = GetDC(0)
    #End If
    dpiY = GetDeviceCaps(hDC, LOGPIXELSY)
    fontSize = Abs(ncm.lfMessageFont.lfHeight) * 72 / dpiY
    Call ReleaseDC(0, hDC)
    
    GetMsgBoxFont = Array(fontName, fontSize)
End Function

' 调用示例
Sub TestGetFont()
    Dim fontInfo As Variant
    fontInfo = GetMsgBoxFont()
    MsgBox "当前系统MsgBox字体：" & fontInfo(0) & "，字号：" & fontInfo(1)
End Sub

低成本替代方案 #

如果你不需要100%适配所有修改过系统字体的特殊设备，直接把自定义表单的字体设置为Segoe UI 9号即可，该配置覆盖了95%以上Win7及更高版本系统的默认场景，开发效率比调用API高很多。

内容的提问来源于stack exchange，提问作者k1dfr0std