这里新注册了绝望的用户。
我很久以前离开了编程行业,但现在又被要求做一些改进等。
我想使用注册表来存储一些文件位置,因此用户不必一直指定它们。我想将它们存储在HKEY_LOCAL_MACHINE下,因为有多个用户。
我已经使用RegCreateKeyEx创建了密钥,并且已经使用RegSetValueExString将一个值输入到密钥中,因此HKEY_LOCAL_MACHINE下有一个名为SUPPLIERFILE的密钥,其值为“ C:\ Documents and Settings ..”等。
但是,当我使用RegQueryValueExString时,它不起作用:lpValue字符串为空,尽管cbdata确实包含我期望在那里找到的字符串的长度。记录的错误是234,ERROR_MORE_DATA。
我尝试使用RegGetValue,因为我认为可能是非空终止的字符串是问题,但我在api dll中没有RegGetValue。
即使按照如何用null终止字符串的方式,也将不胜感激地收到任何建议。谢谢,史蒂夫
您的错误表示您尚未初始化足够大的字符串缓冲区供API函数使用,但是没有您的代码,???我从使用的注册表实用程序类中提取了以下代码。我想我已经包括了所有API声明和使用的常量,以及将返回的错误转换为有用的方法的方法。
Public Enum RegRootKey
HKEY_CLASSES_ROOT = &H80000000
HKEY_CURRENT_CONFIG = &H80000005
HKEY_CURRENT_USER = &H80000001
HKEY_DYN_DATA = &H80000006
HKEY_LOCAL_MACHINE = &H80000002
HKEY_PERFORMANCE_DATA = &H80000004
HKEY_USERS = &H80000003
End Enum
'the following declare is used to return windows error descriptions
Private Declare Function FormatMessage Lib "Kernel32" Alias "FormatMessageA" (ByVal dwFlags As Long, lpSource As Any, ByVal dwMessageId As Long, ByVal dwLanguageId As Long, ByVal lpBuffer As String, ByVal nSize As Long, Arguments As Long) As Long
Private Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000
Private Const FORMAT_MESSAGE_IGNORE_INSERTS = &H200
'key constants
Private Const ERROR_NO_MORE_ITEMS = 259&
Private Const ERROR_MORE_DATA = 234
Private Const ERROR_SUCCESS = 0&
Private Const SYNCHRONIZE = &H100000
Private Const READ_CONTROL = &H20000
Private Const READ_WRITE = 2
Private Const READAPI = 0
Private Const STANDARD_RIGHTS_ALL = &H1F0000
Private Const STANDARD_RIGHTS_REQUIRED = &HF0000
Private Const STANDARD_RIGHTS_EXECUTE = (READ_CONTROL)
Private Const STANDARD_RIGHTS_READ = (READ_CONTROL)
Private Const STANDARD_RIGHTS_WRITE = (READ_CONTROL)
Private Const KEY_NOTIFY = &H10
Private Const KEY_QUERY_VALUE = &H1
Private Const KEY_CREATE_LINK = &H20
Private Const KEY_CREATE_SUB_KEY = &H4
Private Const KEY_ENUMERATE_SUB_KEYS = &H8
Private Const KEY_EVENT = &H1
Private Const KEY_SET_VALUE = &H2
Private Const KEY_ALL_ACCESS = ((STANDARD_RIGHTS_ALL Or KEY_QUERY_VALUE Or KEY_SET_VALUE Or KEY_CREATE_SUB_KEY Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY Or KEY_CREATE_LINK) And (Not SYNCHRONIZE))
Private Const KEY_READ = ((STANDARD_RIGHTS_READ Or KEY_QUERY_VALUE Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY) And (Not SYNCHRONIZE))
Private Const KEY_EXECUTE = ((KEY_READ) And (Not SYNCHRONIZE))
Private Const KEY_WRITE = ((STANDARD_RIGHTS_WRITE Or KEY_SET_VALUE Or KEY_CREATE_SUB_KEY) And (Not SYNCHRONIZE))
Private Const REG_OPTION_NON_VOLATILE = 0
Private Const REG_SZ = 1 ' Unicode nul terminated string
Private Const REG_BINARY = 3
Private Const REG_DWORD = 4
Private Const REG_MULTI_SZ = 7 ' Multiple Unicode strings
Private Const REG_NONE = 0 ' No value type
Private Const KEY_WOW64_64KEY As Long = &H100& '32 bit app to access 64 bit hive
Private Const KEY_WOW64_32KEY As Long = &H200& '64 bit app to access 32 bit hive
'API declarations
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey 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 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 RootKeyName Lib "advapi32.dll" Alias "RootKeyNameA" (ByVal lphKey As RegRootKey) As String
Public Function GetStringValue(ByVal hKeyRoot As RegRootKey, ByVal hKeySubKey As String, ByVal ValueName As String, Optional ByVal Default As String) As String
Dim strReturn As String
Dim strBuffer As String
Dim lngType As Long
Dim lngBufLen As Long
Dim lngRst As Long
Dim hKeyHandle As Long
On Error GoTo errGetStringValue
'just to avoid any errors in calling functions using a ubound to check the contents
strBuffer = String(255, vbNullChar)
lngBufLen = Len(strBuffer)
lngRst = RegOpenKeyEx(hKeyRoot, hKeySubKey, 0, KEY_READ Or KEY_WOW64_64KEY, hKeyHandle)
If hKeyHandle <> 0 Then
If StrComp(ValueName, "default", vbTextCompare) = 0 Then
lngRst = RegQueryValueEx(hKeyHandle, "", ByVal 0&, lngType, ByVal strBuffer, lngBufLen)
Else
lngRst = RegQueryValueEx(hKeyHandle, ValueName, ByVal 0&, lngType, ByVal strBuffer, lngBufLen)
End If
End If
If lngRst = 0 Then
If lngType = REG_SZ Then
If lngBufLen > 0 Then
strReturn = Left$(strBuffer, lngBufLen - 1)
Else
strReturn = Default
End If
Else
Err.Raise 1, App.EXEName, FormatClassError(1)
End If
ElseIf lngRst = 2 Then 'the key does not exists so return the default
strReturn = Default
Else 'if the return is non-zero there was an error
Err.Raise lngRst, App.EXEName, "There was an error reading the " & RootKeyName(hKeyRoot) & "\" & _
hKeySubKey & " registry key, " & LCase$(FormatClassError(lngRst))
End If
If hKeyHandle <> 0 Then
lngRst = RegCloseKey(hKeyHandle)
hKeyHandle = 0
End If
GetStringValue = strReturn
Exit Function
errGetStringValue:
If hKeyHandle <> 0 Then
lngRst = RegCloseKey(hKeyHandle)
hKeyHandle = 0
End If
Err.Raise Err.Number, Err.Source & ":GetStringValue", Err.Description
End Function
Private Function FormatClassError(ByVal ErrorNumber As Long) As String
Dim strReturn As String
Dim strBuffer As String
Dim lngBufLen As Long
Dim lngRst As Long
On Error Resume Next
'initialize the buffer to to API function
strBuffer = String(1024, vbNullChar)
lngBufLen = Len(strBuffer)
'make the call to the API function
lngRst = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS, ByVal 0&, ErrorNumber, ByVal 0&, strBuffer, lngBufLen, ByVal 0&)
'if the return value is <> 0 then we have a valid message
If lngRst <> 0 Then
strReturn = Left$(strBuffer, lngRst)
Else
'make another call to the API function with the last dll error
lngRst = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS, ByVal 0&, Err.LastDllError, ByVal 0&, strBuffer, lngBufLen, ByVal 0&)
If lngRst <> 0 Then
strReturn = Left$(strBuffer, lngRst)
Else
strReturn = "Unable to retrieve error description."
End If
End If
'return the result
FormatClassError = strReturn
End Function
您应该首先检查注册表是否确实存在。通过错误处理,我们可以检查注册表项。
Private Function RegOSInfo(RegPath As String, RegKey As String) As String
On Error GoTo ErrHandler
Dim osName As String
Dim Reg As Object
Set Reg = CreateObject("WScript.Shell")
RegOSInfo = Reg.RegRead(RegPath & "\" & RegKey)
ErrHandler:
RegOSInfo = "-555" 'custom Error Code, Registry key doesn't exist
End Function
您可以根据需要处理自定义错误代码。