我有一个用fortran编写的DLL我知道可行,因为我从一个我们日常使用的工作软件包中获取它。我试图从任何东西调用它,但我有问题我相信通过正确格式化的参数进出它,所以我决定尝试从VB程序访问它。我之所以选择VB,是因为我联系了我们正在使用的软件包的开发人员,他在VB6中给了我他的DLL函数调用,即使他不允许向我展示FORTRAN源代码。
问题是(或许,我认为)我在VB.NET中编写,它具有与VB6不同的数据类型。谁能明白为什么我遇到了问题。
运行时出现的错误是:“AccessViolationException未处理:尝试读取或写入受保护的内存。这通常表示其他内存已损坏。”
这是我提供的函数调用:
Declare Sub FCC_Curves Lib "FCC_Curves.dll" (Read_Flag As Boolean, First_Flag As Boolean, Frequency_MHz As Single, IQT As Integer, ByVal Radiation_Opt As String, ByVal L1 As Long, ERP_Watts As Single, T_PowerWatts As Single, Tx_GaindBi As Single, T_Loss As Single, ByVal Service As String, ByVal L2 As Long, Reliability As Integer, ByVal FCC_CurvesDataPath As String, ByVal L3 As Long, ByVal TerrainRoughness As String, ByVal L4 As Long, Haatm As Single, NPRfl As Integer, NFCCCurve As Integer, HPRfl As Single, Crve As Single, FCC_Loss As Single, Code As Integer, FS As Single)
这是我的代码:
Module Module1
Declare Sub FCC_Curves Lib "FCC_Curves.dll" (ByVal Read_Flag As Boolean, ByVal First_Flag As Boolean, ByVal Frequency_MHz As Single, ByVal IQT As Int16, ByVal Radiation_Opt As String, ByVal L1 As Int32, ByVal ERP_Watts As Single, ByVal T_PowerWatts As Single, ByVal Tx_GaindBi As Single, ByVal T_Loss As Single, ByVal Service As String, ByVal L2 As Int32, ByVal Reliability As Int16, ByVal FCC_CurvesDataPath As String, ByVal L3 As Int32, ByVal TerrainRoughness As String, ByVal L4 As Int32, ByVal Haatm As Single, ByVal NPRfl As Int16, ByVal NFCCCurve As Int16, ByVal HPRfl() As Single, ByVal Crve() As Single, ByRef FCC_Loss As Single, ByRef Code As Int16, ByRef FS() As Single)
Sub Main()
Dim Read_Flag As Boolean
Dim First_Flag As Boolean
Dim Frequency_MHz As Single
Dim IQT As Int16
Dim Radiation_Opt As String
Dim L1 As Int32
Dim ERP_Watts As Single
Dim T_PowerWatts As Single
Dim Tx_GaindBi As Single
Dim T_Loss As Single
Dim Service As String
Dim L2 As Int32
Dim Reliability As Int16
Dim FCC_CurvesDataPath As String
Dim L3 As Int32
Dim TerrainRoughness As String
Dim L4 As Int32
Dim Haatm As Single
Dim NPRfl As Int16
Dim NFCCCurve As Int16
Dim HPRfl(12) As Single
Dim Crve(5) As Single
Dim FCC_Loss As Single
Dim Code As Int16
Dim FS(15) As Single
'Dim HPRfl As Single
'Dim Crve As Single
'Dim FCC_Loss As Single
'Dim Code As Int16
'Dim FS As Single
Read_Flag = True
First_Flag = True
Frequency_MHz = 98.1
IQT = 0
Radiation_Opt = "ERP"
L1 = 3
ERP_Watts = 1000
T_PowerWatts = 1000
Tx_GaindBi = 2.15
T_Loss = 0
Service = "Broadcast"
L2 = 9
Reliability = 50
FCC_CurvesDataPath = "C:\Program Files\CSPT_Extension\data\"
L3 = 37
TerrainRoughness = "Off"
L4 = 3
Haatm = 1500
NPRfl = 13
NFCCCurve = 6
Dim i As Int16
HPRfl(0) = 11
HPRfl(1) = 128
For i = 2 To 12
HPRfl(i) = 1500
Next
For i = 0 To 5
Crve(i) = i * 15
Next
FCC_Curves(Read_Flag, First_Flag, Frequency_MHz, IQT, Radiation_Opt, L1, ERP_Watts, T_PowerWatts, Tx_GaindBi, T_Loss, Service, L2, Reliability, FCC_CurvesDataPath, L3, TerrainRoughness, L4, Haatm, NPRfl, NFCCCurve, HPRfl, Crve, FCC_Loss, Code, FS)
End Sub
End Module
答案 0 :(得分:3)
我找到了解决方案。在VB6中,默认情况下,未以其他方式指定的参数作为ByRef传递给函数。在VB.NET中,如果在函数声明中将参数留空,它会自动插入ByVal,因此它似乎是默认的事实。 VB.NET强制你指定,换句话说,如果你从VB6到VB.NET的函数声明,知道VB6中未标记的默认值是ByRef。
答案 1 :(得分:1)
是的,VB.NET数据类型与VB6数据类型不兼容。 VB6 Integer现在是Short(又名Int16)。 VB6 Long现在是一个Integer(又名Int32)。 VB6布尔值是一个奇怪的鸭子,现在相当于Short,其中值True为-1,False为0。
首先将函数声明中的Long更改为Integer,即Big One。
答案 2 :(得分:0)
有时需要在带有字符串参数的外部函数中使用Auto关键字。
Declare Auto Sub FCC_Curves Lib...