VB6-与native-dll交互

1. 调用Sleep函数

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Public Console As CConsole
Public Sub Main()
        Set Console = New CConsole
        ' 睡眠线程1s
        Sleep 1000
        Console.WriteLine 11
End Sub

 

 

2. 调用自己写的(add(1, 2))

cpp

// VB6只支持__stdcall调用
extern "C" __declspec(dllexport) int  __stdcall  add(int a, int b) {
    return a + b;
}

生成的dll需要通过exescope工具查看导出的函数名称。或者可以自己写def文件或者#prgama编译宏

 

 

VB6

Private Declare Function addLibCpp Lib _
"C:\Users\Administrator\source\repos\VB6CppInter\Release\VB6CppInter" Alias "_add@8" (ByVal a As Integer, ByVal b As Integer) As Integer

Public Sub Main()
　　Set Console = New CConsole
　　Dim a As Integer
　　Dim b As Integer
　　a = 1
　　b = 2
　　Console.WriteLine (addLibCpp(a, b))
　　Console.ReadKey

End Sub

 

 

3.  指针

cpp

extern "C" __declspec(dllexport) void  __stdcall getStrLength(int *strlength, const char *str) {
    *strlength = strlen(str);
}

 

vb6

Public Console As CConsole
Private Declare Sub getStrLength Lib _
"C:\Users\Administrator\source\repos\VB6CppInter\Release\VB6CppInter" Alias "_getStrLength@8" (ByRef StrLength As Long, ByVal b As String)

Public Sub Main()
    Set Console = New CConsole
    Dim StrLength As Long
    getStrLength StrLength, "helloworld"
    Console.WriteLine (StrLength)  ' 10
    Console.ReadKey
End Sub