什么是VB6等价的C ++ char数组？ [英] What's is the VB6 equivalent of a C++ char array?

问题描述

我试图从VB6应用程序中调用用C ++编写的DLL。

I'm trying to call a DLL written in C++ from a VB6 application.

这是调用DLL的C ++示例代码。

Here's the C++ example code for calling the DLL.

char firmware[32];
int maxUnits = InitPowerDevice(firmware);

< DLL调用约定。

Public Declare Function InitPowerDevice Lib "PwrDeviceDll.dll" (ByRef firmware() As Byte) As Long

Dim firmware(32) As Byte
InitPowerDevice(firmware)

编辑：C ++原型：

Name: InitPowerDevice
Parameters: firmware: returns firmware version in ?.? format in a character string (major revision and minor revision)
Return: >0 if successful. Returns number of Power devices connected

CLASS_DECLSPEC int InitPowerDevice(char firmware[]);

推荐答案

很久了，

// In the C code when compiling to build the dll
CLASS_DECLSPEC int __stdcall InitPowerDevice(char firmware[]);

' VB Declaration
Public Declare Function InitPowerDevice Lib "PwrDeviceDll.dll" _
        (ByVal firmware As String) As Long

' VB Call
Dim fmware as String
Dim r  as Long
fmware = Space(32)
r = InitPowerDevice(fmware)

我不认为VB6支持以任何正常方式调用 cdecl 函数 - 可能有hacks做。可能你可以写一个包装 dll ，它包含 cdecl 函数和 stdcall 函数并转发这个调用。

I don't think VB6 supports calling cdecl functions in any normal way - there may be hacks for doing it. May be you can write a wrapper dll which wraps the cdecl function with a stdcall function and just forwards the call.

这些是一些黑客 - 但我没有尝试过。

These are some hacks - but I haven't tried it.

http：// planet- source-code.com/vb/scripts/ShowCode.asp?txtCodeId=49776&lngWId=1

http://planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId = 62014& lngWId = 1

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