关于vb.net枚举带属性的信息

VB.net如何枚举字符串？

Enum Week

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周日 = 0

周一 = 1

周二 = 2

周三 = 3

周四 = 4

周五 = 5

周六 = 6

End Enum

Sub Main()

Dim myType As Type = GetType(Week)

MsgBox(Week.GetName(myType, Week.周二))

End Sub

怎样用VB脚本枚举注册表属性

Option Explicit

'注册表主键

Public Enum enumRegMainKey

iHKEY_CURRENT_USER = H80000001

iHKEY_LOCAL_MACHINE = H80000002

iHKEY_CLASSES_ROOT = H80000000

iHKEY_CURRENT_CONFIG = H80000005

iHKEY_USERS = H80000003

End Enum

'注册表数据类型

Public Enum enumRegSzType

iREG_SZ = H1

iREG_EXPAND_SZ = H2

iREG_BINARY = H3

iREG_DWORD = H4

iREG_NONE = 0

iREG_DWORD_LITTLE_ENDIAN = 4

iREG_DWORD_BIG_ENDIAN = 5

iREG_LINK = 6

iREG_MULTI_SZ = 7

iREG_RESOURCE_LIST = 8

iREG_FULL_RESOURCE_DESCRIPTOR = 9

iREG_RESOURCE_REQUIREMENTS_LIST = 10

End Enum

'注册表

Private Const ERROR_SUCCESS = 0

Private Const ERROR_BADDB = 1009

Private Const ERROR_BADKEY = 1010

Private Const ERROR_CANTOPEN = 1011

Private Const ERROR_CANTREAD = 1012

Private Const ERROR_CANTWRITE = 1013

Private Const ERROR_OUTOFMEMORY = 14

Private Const ERROR_INVALID_PARAMETER = 87

Private Const ERROR_ACCESS_DENIED = 5

Private Const ERROR_NO_MORE_ITEMS = 259

Private Const ERROR_MORE_DATA = 234

Private Const KEY_QUERY_VALUE = H1

Private Const KEY_SET_VALUE = H2

Private Const KEY_CREATE_SUB_KEY = H4

Private Const KEY_ENUMERATE_SUB_KEYS = H8

Private Const KEY_NOTIFY = H10

Private Const KEY_CREATE_LINK = H20

Private Const SYNCHRONIZE = H100000

Private Const READ_CONTROL = H20000

Private Const WRITE_DAC = H40000

Private Const WRITE_OWNER = H80000

Private Const STANDARD_RIGHTS_REQUIRED = HF0000

Private Const STANDARD_RIGHTS_READ = READ_CONTROL

Private Const STANDARD_RIGHTS_WRITE = READ_CONTROL

Private Const STANDARD_RIGHTS_EXECUTE = READ_CONTROL

Private Const KEY_READ = STANDARD_RIGHTS_READ Or KEY_QUERY_VALUE Or KEY_ENUMERATE_SUB_KEYS Or KEY_NOTIFY

Private Const KEY_WRITE = STANDARD_RIGHTS_WRITE Or KEY_SET_VALUE Or KEY_CREATE_SUB_KEY

Private Const KEY_EXECUTE = KEY_READ

Private Declare Function RegCreateKey Lib "advapi32.dll" Alias "RegCreateKeyA" (ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long

Private Declare Function RegCreateKeyEx Lib "advapi32.dll" Alias "RegCreateKeyExA" (ByVal hKey As Long, ByVal lpSubKey As String, ByVal Reserved As Long, ByVal lpClass As String, ByVal dwOptions As Long, ByVal samDesired As Long, lpSecurityAttributes As SECURITY_ATTRIBUTES, phkResult As Long, lpdwDisposition As Long) As Long

Private Declare Function RegEnumValue Lib "advapi32.dll" Alias "RegEnumValueA" (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpValueName As String, lpcbValueName As Long, ByVal lpReserved As Long, lpType As Long, lpData As Byte, lpcbData As Long) As Long

Private Declare Function RegEnumKeyEx Lib "advapi32.dll" Alias "RegEnumKeyExA" (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String, lpcbName As Long, ByVal lpReserved As Long, ByVal lpClass As String, lpcbClass As Long, lpftLastWriteTime As FILETIME) 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 RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long

Private Declare Function RegDeleteValue Lib "advapi32.dll" Alias "RegDeleteValueA" (ByVal hKey As Long, ByVal lpValueName As String) As Long

Private Declare Function RegSetValueEx Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByVal lpData As String, ByVal cbData As Long) As Long

Private Declare Function RegSetValueExLong Lib "advapi32.dll" Alias "RegSetValueExA" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, lpData As Long, ByVal cbData As Long) As Long

Private Declare Function RegSetValueExA Lib "advapi32.dll" (ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, ByVal dwType As Long, ByRef lpData As Long, ByVal cbData 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 ' Note that if you declare the lpData parameter as String, you must pass it By Value.

Private Declare Function RegDeleteKey Lib "advapi32.dll" Alias "RegDeleteKeyA" (ByVal hKey As Long, ByVal lpSubKey As String) As Long

Private Declare Function RegSaveKey Lib "advapi32.dll" Alias "RegSaveKeyA" (ByVal hKey As Long, ByVal lpFile As String, ByVal lpSecurityAttributes As Long) As Long

Private Declare Function RegRestoreKey Lib "advapi32.dll" Alias "RegRestoreKeyA" (ByVal hKey As Long, ByVal lpFile As String, ByVal dwflags As Long) As Long

Private Type FILETIME

dwLowDateTime As Long

dwHighDateTime As Long

End Type

Private Type SECURITY_ATTRIBUTES

nLength As Long

lpSecurityDescriptor As Long

bInheritHandle As Boolean

End Type

Public Function GetValue(ByVal mainKey As enumRegMainKey, _

ByVal subKey As String, _

ByVal keyV As String, _

ByRef sValue As Variant, _

Optional ByRef rlngErrNum As Long, _

Optional ByRef rstrErrDescr As String) As Boolean

Dim hKey As Long, lType As Long, lBuffer As Long, sBuffer As String, lData As Long

On Error GoTo GetValueErr

GetValue = False

If RegOpenKeyEx(mainKey, subKey, 0, KEY_READ, hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

If RegQueryValueEx(hKey, keyV, 0, lType, ByVal 0, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

Select Case lType

Case iREG_SZ

lBuffer = 255

sBuffer = Space(lBuffer)

If RegQueryValueEx(hKey, keyV, 0, lType, ByVal sBuffer, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

sValue = Left(sBuffer, InStr(sBuffer, Chr(0)) - 1)

Case iREG_EXPAND_SZ

sBuffer = Space(lBuffer)

If RegQueryValueEx(hKey, keyV, 0, lType, ByVal sBuffer, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

sValue = Left(sBuffer, InStr(sBuffer, Chr(0)) - 1)

Case iREG_DWORD

If RegQueryValueEx(hKey, keyV, 0, lType, lData, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

sValue = lData

Case iREG_BINARY

If RegQueryValueEx(hKey, keyV, 0, lType, lData, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

sValue = lData

End Select

If RegCloseKey(hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "获取注册表值时出错"

End If

GetValue = True

Err.Clear

GetValueErr:

rlngErrNum = Err.Number

rstrErrDescr = Err.Description

End Function

Public Function SetValue(ByVal mainKey As enumRegMainKey, _

ByVal subKey As String, _

ByVal keyV As String, _

ByVal lType As enumRegSzType, _

ByVal sValue As Variant, _

Optional ByRef rlngErrNum As Long, _

Optional ByRef rstrErrDescr As String) As Boolean

Dim S As Long, lBuffer As Long, hKey As Long

Dim ss As SECURITY_ATTRIBUTES

On Error GoTo SetValueErr

SetValue = False

ss.nLength = Len(ss)

ss.lpSecurityDescriptor = 0

ss.bInheritHandle = True

If RegCreateKeyEx(mainKey, subKey, 0, "", 0, KEY_WRITE, ss, hKey, S) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

Select Case lType

Case iREG_SZ

lBuffer = LenB(sValue)

If RegSetValueEx(hKey, keyV, 0, lType, ByVal sValue, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

Case iREG_EXPAND_SZ

lBuffer = LenB(sValue)

If RegSetValueEx(hKey, keyV, 0, lType, ByVal sValue, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

Case iREG_DWORD

lBuffer = 4

If RegSetValueExA(hKey, keyV, 0, lType, sValue, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

Case iREG_BINARY

lBuffer = 4

If RegSetValueExA(hKey, keyV, 0, lType, sValue, lBuffer) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

Case Else

Err.Raise vbObjectError + 1, , "不支持该参数类型"

End Select

If RegCloseKey(hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "设置注册表时出错"

End If

SetValue = True

Err.Clear

SetValueErr:

rlngErrNum = Err.Number

rstrErrDescr = Err.Description

End Function

Public Function DeleteValue(ByVal mainKey As enumRegMainKey, _

ByVal subKey As String, _

ByVal keyV As String, _

Optional ByRef rlngErrNum As Long, _

Optional ByRef rstrErrDescr As String) As Boolean

Dim hKey As Long

On Error GoTo DeleteValueErr

DeleteValue = False

If RegOpenKeyEx(mainKey, subKey, 0, KEY_WRITE, hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

If RegDeleteValue(hKey, keyV) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

If RegCloseKey(hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

DeleteValue = True

Err.Clear

DeleteValueErr:

rlngErrNum = Err.Number

rstrErrDescr = Err.Description

End Function

Public Function DeleteKey(ByVal mainKey As enumRegMainKey, _

ByVal subKey As String, _

ByVal keyV As String, _

Optional ByRef rlngErrNum As Long, _

Optional ByRef rstrErrDescr As String) As Boolean

Dim hKey As Long

On Error GoTo DeleteKeyErr

DeleteKey = False

If RegOpenKeyEx(mainKey, subKey, 0, KEY_WRITE, hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

If RegDeleteKey(hKey, keyV) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

If RegCloseKey(hKey) ERROR_SUCCESS Then

Err.Raise vbObjectError + 1, , "删除注册表值时出错"

End If

DeleteKey = True

Err.Clear

DeleteKeyErr:

rlngErrNum = Err.Number

rstrErrDescr = Err.Description

End Function

VB.NET的枚举求教解决方法

这个功能实现起来其实也很简单，就是通过反射去读取 DescriptionAttribute 的 Description 属性的值，代码如下所示：

/// summary

/// 返回枚举项的描述信息。

/// /summary

/// param name="value"要获取描述信息的枚举项。/param

/// returns枚举想的描述信息。/returns

public static string GetDescription(Enum value)

{

Type enumType = value.GetType();

// 获取枚举常数名称。

string name = Enum.GetName(enumType, value);

if (name != null)

{

// 获取枚举字段。

FieldInfo fieldInfo = enumType.GetField(name);

if (fieldInfo != null)

{

// 获取描述的属性。

DescriptionAttribute attr = Attribute.GetCustomAttribute(fieldInfo,

typeof(DescriptionAttribute), false) as DescriptionAttribute;

if (attr != null)

{

return attr.Description;

}

}

}

return null;

}

这段代码还是很容易看懂的，这里取得枚举常数的名称使用的是 Enum.GetName() 而不是 ToString()，因为前者更快，而且对于不是枚举常数的值会返回 null，不用进行额外的反射。

当然，这段代码仅是一个简单的示例，接下来会进行更详细的分析。

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