VB的写法，关于版本写入注册表

'软件都有一个关于咱们的菜单，单单实现这个功能并不难，困难的是可以将这些信息写入注册表中，这样每次只要弹出这样的窗口，就从注册表里去搜索。这样是否是极大的节省了资源。
这里也是一种通用的用法，例子比较初级。下面是所有的代码：
Option Explicit

' 注册表关键字安全选项...
Const READ_CONTROL = &H20000
Const KEY_QUERY_VALUE = &H1
Const KEY_SET_VALUE = &H2
Const KEY_CREATE_SUB_KEY = &H4
Const KEY_ENUMERATE_SUB_KEYS = &H8
Const KEY_NOTIFY = &H10
Const KEY_CREATE_LINK = &H20
Const KEY_ALL_ACCESS = KEY_QUERY_VALUE + KEY_SET_VALUE + _
                       KEY_CREATE_SUB_KEY + KEY_ENUMERATE_SUB_KEYS + _
                       KEY_NOTIFY + KEY_CREATE_LINK + READ_CONTROL
                     
' 注册表关键字 ROOT 类型...
Const HKEY_LOCAL_MACHINE = &H80000002
Const ERROR_SUCCESS = 0
Const REG_SZ = 1                         ' 独立的空的终结字符串
Const REG_DWORD = 4                      ' 32位数字

Const gREGKEYSYSINFOLOC = "SOFTWARE\Microsoft\Shared Tools Location"
Const gREGVALSYSINFOLOC = "MSINFO"
Const gREGKEYSYSINFO = "SOFTWARE\Microsoft\Shared Tools\MSINFO"
Const gREGVALSYSINFO = "PATH"

Private Declare Function RegOpenKeyEx Lib "advapi32" Alias "RegOpenKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal ulOptions As Long, ByVal samDesired As Long, ByRef phkResult As Long) As Long
Private Declare Function RegQueryValueEx Lib "advapi32" Alias "RegQueryValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long, ByRef lpType As Long, ByVal lpData As String, ByRef lpcbData As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32" (ByVal hKey As Long) As Long


Private Sub cmdSysInfo_Click()
  Call StartSysInfo
End Sub

Private Sub cmdOK_Click()
  Unload Me
End Sub

Private Sub Form_Load()
On Error Resume Next
    Me.Caption = GetLang("lang_abbout_title")
    lblVersion.Caption = GetLang("lang_version") & App.Major & "." & App.Minor & "." & App.Revision
    lblTitle.Caption = GetLang("lang_appname")
    ImageLogo.Picture = LoadPicture(App.Path & "\logo.jpg")
    cmdOK.Caption = GetLang("lang_confirm")
    lblDescription.Caption = GetLang("lang_lblDescription")
    lblContact.Caption = GetLang("lang_lblContact")
End Sub

Public Sub StartSysInfo()
    On Error GoTo SysInfoErr
  
    Dim rc As Long
    Dim SysInfoPath As String
    
    ' 试图从注册表中得到系统信息程序的路径及名称...
    If GetKeyValue(HKEY_LOCAL_MACHINE, gREGKEYSYSINFO, gREGVALSYSINFO, SysInfoPath) Then
    ' 试图仅从注册表中得到系统信息程序的路径...
    ElseIf GetKeyValue(HKEY_LOCAL_MACHINE, gREGKEYSYSINFOLOC, gREGVALSYSINFOLOC, SysInfoPath) Then
        ' 已知32位文件版本的有效位置
        If (Dir(SysInfoPath & "\MSINFO32.EXE") <> "") Then
            SysInfoPath = SysInfoPath & "\MSINFO32.EXE"
            
        ' 错误 - 文件不能被找到...
        Else
            GoTo SysInfoErr
        End If
    ' 错误 - 注册表相应条目不能被找到...
    Else
        GoTo SysInfoErr
    End If
    
    Call Shell(SysInfoPath, vbNormalFocus)
    
    Exit Sub
SysInfoErr:
   ' MsgBox "此时系统信息不可用", vbOKOnly
End Sub

Public Function GetKeyValue(KeyRoot As Long, KeyName As String, SubKeyRef As String, ByRef KeyVal As String) As Boolean
    Dim i As Long                                           ' 循环计数器
    Dim rc As Long                                          ' 返回代码
    Dim hKey As Long                                        ' 打开的注册表关键字句柄
    Dim hDepth As Long                                      '
    Dim KeyValType As Long                                  ' 注册表关键字数据类型
    Dim tmpVal As String                                    ' 注册表关键字值的临时存储器
    Dim KeyValSize As Long                                  ' 注册表关键自变量的尺寸
    '------------------------------------------------------------
    ' 打开 {HKEY_LOCAL_MACHINE...} 下的 RegKey
    '------------------------------------------------------------
    rc = RegOpenKeyEx(KeyRoot, KeyName, 0, KEY_ALL_ACCESS, hKey) ' 打开注册表关键字
    
    If (rc <> ERROR_SUCCESS) Then GoTo GetKeyError          ' 处理错误...
    
    tmpVal = String$(1024, 0)                             ' 分配变量空间
    KeyValSize = 1024                                       ' 标记变量尺寸
    
    '------------------------------------------------------------
    ' 检索注册表关键字的值...
    '------------------------------------------------------------
    rc = RegQueryValueEx(hKey, SubKeyRef, 0, _
                         KeyValType, tmpVal, KeyValSize)    ' 得到/建立关键字值
                        
    If (rc <> ERROR_SUCCESS) Then GoTo GetKeyError          ' 处理错误
    
    If (Asc(Mid(tmpVal, KeyValSize, 1)) = 0) Then           ' Win95 外接程序空终结字符串...
        tmpVal = Left(tmpVal, KeyValSize - 1)               ' Null 被找到,从字符串中分离出来
    Else                                                    ' WinNT 没有空终结字符串...
        tmpVal = Left(tmpVal, KeyValSize)                   ' Null 没有被找到, 分离字符串
    End If
    '------------------------------------------------------------
    ' 决定转换的关键字的值类型...
    '------------------------------------------------------------
    Select Case KeyValType                                  ' 搜索数据类型...
    Case REG_SZ                                             ' 字符串注册关键字数据类型
        KeyVal = tmpVal                                     ' 复制字符串的值
    Case REG_DWORD                                          ' 四字节的注册表关键字数据类型
        For i = Len(tmpVal) To 1 Step -1                    ' 将每位进行转换
            KeyVal = KeyVal + hex(Asc(Mid(tmpVal, i, 1)))   ' 生成值字符。 By Char。
        Next
        KeyVal = Format$("&h" + KeyVal)                     ' 转换四字节的字符为字符串
    End Select
    
    GetKeyValue = True                                      ' 返回成功
    rc = RegCloseKey(hKey)                                  ' 关闭注册表关键字
    Exit Function                                           ' 退出
    
GetKeyError:      ' 错误发生后将其清除...
    KeyVal = ""                                             ' 设置返回值到空字符串
    GetKeyValue = False                                     ' 返回失败
    rc = RegCloseKey(hKey)                                  ' 关闭注册表关键字
End Function

平时写惯了代码，也不多去注释什么的，此次为了发表，写了很详尽的注释。代码都比较简单，相信你们也都能看明白。

这段代码也是最近才学会的，之前都是习惯直接去读取软件的相关信息。历来没有去涉及注册表，说到注册表，都会想到特别的难。慢慢学习也发现，不难，至少没有想象中的那么的难。搜了不少资料，看了一些相关的书籍，总结出来的。世上无难事只怕有心人！