如何检查电脑是否安装了 .NET

• 下载演示应用程序 - 24.12 KB
• 下载源代码文件 - 34.57 KB

引言

在本文中，您将看到，在您开始在其他计算机上使用 .NET 应用程序之前，您需要知道该计算机是否具有与您的应用程序请求相同的 .NET Framework 版本。 我在互联网上搜索并找到了关于这个问题的片段，然后完成了它。

背景

我在网上找到的片段显示了在哪里查找以检查 .NET 版本。 在 这个 网站上，它显示了在成功安装 .NET Framework 后创建的特定注册表位置。 剩下的就很容易了。 我查找了一个通过注册表并控制它的特定模块文件。 之后，我稍微完善了一下应用程序，结果... 这是它的工作方式。

Using the Code

创建 VB6 项目后，您必须添加一个模块文件（用于访问和控制注册表项）并粘贴以下代码。 我没有写这个代码，只是在谷歌上搜索了一下。 这是模块代码

' Registry value type definitions
Public Const REG_NONE As Long = 0
Public Const REG_SZ As Long = 1
Public Const REG_EXPAND_SZ As Long = 2
Public Const REG_BINARY As Long = 3
Public Const REG_DWORD As Long = 4
Public Const REG_LINK As Long = 6
Public Const REG_MULTI_SZ As Long = 7
Public Const REG_RESOURCE_LIST As Long = 8

' Registry section definitions
Public Const HKEY_CLASSES_ROOT = &H80000000
Public Const HKEY_CURRENT_USER = &H80000001
Public Const HKEY_LOCAL_MACHINE = &H80000002
Public Const HKEY_USERS = &H80000003
Public Const HKEY_PERFORMANCE_DATA = &H80000004
Public Const HKEY_CURRENT_CONFIG = &H80000005
Public Const HKEY_DYN_DATA = &H80000006

' Codes returned by Reg API calls
Private Const ERROR_NONE = 0
Private Const ERROR_BADDB = 1
Private Const ERROR_BADKEY = 2
Private Const ERROR_CANTOPEN = 3
Private Const ERROR_CANTREAD = 4
Private Const ERROR_CANTWRITE = 5
Private Const ERROR_OUTOFMEMORY = 6
Private Const ERROR_INVALID_PARAMETER = 7
Private Const ERROR_ACCESS_DENIED = 8
Private Const ERROR_INVALID_PARAMETERS = 87
Private Const ERROR_NO_MORE_ITEMS = 259

' Registry API functions used in this module (there are more of them)
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (
    ByVal hKey As Long, ByVal lpSubKey As String, phkResult 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 RegQueryValueEx Lib "advapi32.dll" Alias "RegQueryValueExA" (
    ByVal hKey As Long, ByVal lpValueName As String, ByVal lpReserved As Long,
    lpType As Long, ByVal lpData As String, lpcbData 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,
    ByVal lpData As String, lpcbData As Long) As Long
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
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 RegSetValueExString Lib "advapi32.dll" Alias "RegSetValueExA" (
    ByVal hKey As Long, ByVal lpValueName As String, ByVal Reserved As Long, 
    ByVal dwType As Long, ByVal lpValue 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, lpValue As Long, ByVal cbData As Long) As Long
Private Declare Function RegFlushKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Declare Function RegEnumKey Lib "advapi32.dll" Alias "RegEnumKeyA" (
    ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String,
    ByVal cbName As Long) As Long
Private Declare Function RegDeleteKey Lib "advapi32.dll" Alias "RegDeleteKeyA" (
    ByVal hKey As Long, ByVal lpSubKey As String) As Long
Private Declare Function RegDeleteValue Lib "advapi32.dll" Alias "RegDeleteValueA" (
    ByVal hKey As Long, ByVal lpValueName As String) As Long

' This routine allows you to get values from anywhere in the Registry, it currently
' only handles string, double word and binary values. Binary values are returned as
' hex strings.
'
' Example
' Text1.Text = ReadRegistry(HKEY_LOCAL_MACHINE, 
'   "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon", "DefaultUserName")
'
Public Function ReadRegistry(ByVal Group As Long, ByVal Section As String, 
    ByVal Key As String) As String
Dim lResult As Long, lKeyValue As Long, lDataTypeValue As Long, lValueLength As Long,
    sValue As String, td As Double
On Error Resume Next
lResult = RegOpenKey(Group, Section, lKeyValue)
sValue = Space$(2048)
lValueLength = Len(sValue)
lResult = RegQueryValueEx(lKeyValue, Key, 0&, lDataTypeValue, sValue, lValueLength)
If (lResult = 0) And (Err.Number = 0) Then
   If lDataTypeValue = REG_DWORD Then
      td = Asc(Mid$(sValue, 1, 1)) + &H100& * Asc(Mid$(sValue, 2, 1)) + 
          &H10000 * Asc(Mid$(sValue, 3, 1)) + &H1000000 * CDbl(Asc(Mid$(sValue, 4, 1)))
      sValue = Format$(td, "000")
   End If
   If lDataTypeValue = REG_BINARY Then
       ' Return a binary field as a hex string (2 chars per byte)
       TStr2 = ""
       For i = 1 To lValueLength
          TStr1 = Hex(Asc(Mid(sValue, i, 1)))
          If Len(TStr1) = 1 Then TStr1 = "0" & TStr1
          TStr2 = TStr2 + TStr1
       Next
       sValue = TStr2
   Else
      sValue = Left$(sValue, lValueLength - 1)
   End If
Else
   sValue = "Not Found"
End If
lResult = RegCloseKey(lKeyValue)
ReadRegistry = sValue
End Function		 

之后，您返回到项目的 main form 并使用此模块的工作函数。

如果要检查 .NET v2.0 的安装，请使用此函数的返回值。

ReadRegistry(HKEY_LOCAL_MACHINE, 
    "SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727\", "Install") 

如果要检查 .NET v3.0 的安装，请使用此函数的返回值。

ReadRegistry(HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\", 
    "Install")

如果要检查 .NET v3.5 的安装，请使用此函数的返回值。

ReadRegistry(HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5\", 
    "Install") 

如果要检查 .NET v4.0 的安装，请使用此函数的返回值。

ReadRegistry(HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Client\", 
    "Install") 

用于检查 .NET 版本的四个代码返回 string 值 "001" 或 "Not Installed"。 如果 .NET 存在，它返回 "001" 值，如果不存在，您就知道了剩下的... 玩得开心...

历史

• 2010年11月24日：初始帖子