用VBA检查某个软件是否安装及其安装路径

• 前言
• 实现
• 解释

前言

有时候需要用VBA启动其它程序处理事情，例如整个处理流程中需要先解压缩文件。此时，主动探测用户电脑上是否已安装相应的软件及安装位置就比较重要。

实现

通过调用Windows API来实现

Private Declare Function RegOpenKeyEx Lib "advapi32.dll" Alias "RegOpenKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, phkResult As Long) As Long
Private Declare Function RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Const REG_SZ                As Long = 1
Private Const KEY_QUERY_VALUE       As Long = &H1
Private Const HKEY_LOCAL_MACHINE    As Long = &H80000002


Function GetAppPath(ByVal AppName As String) As String
    Dim hKey        As Long
    Dim lType       As Long
    Dim lSize       As Long
    Dim sSubKey     As String
    Dim sBuffer     As String
     
    sSubKey = "Software\Microsoft\Windows\CurrentVersion\App Paths\" & AppName
     
    If RegOpenKeyEx(HKEY_LOCAL_MACHINE, sSubKey, 0, KEY_QUERY_VALUE, hKey) = 0 Then
        If RegQueryValueEx(hKey, vbNullString, 0, lType, ByVal 0&, lSize) = 0 Then
            If lType = REG_SZ And lSize > 0 Then
                sBuffer = Space$(lSize)
                If RegQueryValueEx(hKey, vbNullString, 0, lType, ByVal sBuffer, lSize) = 0 Then
                    GetAppPath = Trim(Replace(Trim(Left$(sBuffer, lSize - 1)), "\" & AppName, ""))
                End If
            End If
         End If
    End If
     
End Function


Sub Test()
	Dim strAppPath as String
	strAppPath = GetAppPath("7zFM.exe") '检查压缩软件7-Zip的安装路径，7-zip的程序名是7zFM.exe
	If strAppPath = "" Then MsgBox "本电脑上没有安装7-Zip！"
End Sub

解释

关于advapi.dll，可以参考其它文章advapi.dll