Question

我有一个.ini文件设置，我从中读取连接字符串。我有一个模型来读取字符串：

Option Explicit

Private Declare Function GetPrivateProfileString Lib "kernel32" _
    Alias "GetPrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As Any _
    , ByVal lpDefault As String, ByVal lpReturnedString As String, ByVal nSize As Long _
    , ByVal lpFileName As String) As Long


Public Const iniPath = "\DBSettings.INI"


Public Sub Main()
Dim dbPath As String
Dim dbPath As String
dbPath = GetSetting("DataBase", "DBPath")
dbPath= GetSetting("DataBase", "DBPath")
Form1.Show

 End Sub


Private Function GetSetting(ByVal pHeading As String, ByVal pKey As String) As String
Const cparmLen = 100
Dim sReturn As String * cparmLen
Dim sDefault As String * cparmLen
Dim aLength As Long
aLength = GetPrivateProfileString(pHeading, pKey _
            , sDefault, sReturn, cparmLen, App.Path & iniPath)
GetSetting = Mid(sReturn, 1, aLength)
End Function

现在，我试图在点击按钮时显示字符串：

Option Explicit

Public Sub Command1_Click()

MsgBox (dbPath)
MsgBox (dbPath)

End Sub

但是，似乎表单无法看到模块中的变量。我该如何解决这个问题？任何帮助将不胜感激。

Answer 1

dbPath在sub中声明，因此范围规则规定变量仅存在于该子变量中。

要使变量可见，请在具有public访问修饰符的模块中声明它：

public dbPath as string

然后移除dim

中的main()

Answer 2

DBPath是过程范围变量，因为它在过程（Sub Main（））中声明。它不会从其他模块，甚至模块本身看到。而且，您不能在Procedure（Sub或Function）中声明Public变量。

有关变量范围的更多信息： http://msdn.microsoft.com/en-us/library/1t0wsc67.aspx

从.INI文件中读取连接字符串

2 个答案: