VC 制作的dll,返回值为uchar,在VB中如何定义和得到正确结果

[chuting1]

在VC中函数定义为
rdcard(int icDev,uchar * cardlx)

在VC的DEMO中,执行后,cardlx可直接得到诸如12345,yfd等字符串

在VB中定义
Declare Function rdcard Lib "rwcard.dll" (ByVal icDev As Long, ByRef cardlx As String) As Integer

DEMO中,
Dim ads As String
aa = rdcompany(514, ads)
程序执行即飞

而在VB中定义
Declare Function rdcard Lib "rwcard.dll" (ByVal icDev As Long, ByRef cardlx As byte) As Integer

DEMO中,
Dim aaa(50) As Byte
aa = rdcompany(514, aaa(0))
方可

这样的话,如果cardlx是个不定长的字符,要想得到就很麻烦,请问有什么办法解决吗

[浅蓝马]

Declare Function rdcard Lib "rwcard.dll" (ByVal icDev As Long, ByRef cardlx As String) As Integer

Dim ads As String * 256
aa = rdcompany(514, ads)

[chuting1]

楼上两位的都不对啊

[chenhui530]

你认真看我的声明

call rdcompany(512,strptr("1233"))

[chuting1]

ByVal cardlx As long ???
strptr ???

[chuting1]

最终我要得到cardlx的字符值,定义成long,那strptr(参数为strting)怎么用呢

[chenhui530]

Declare Function rdcard Lib "rwcard.dll" (ByVal icDev As Long, ByVal cardlx As long) As Integer

[chenhui530]

cardlx 传strptr后得到的地址

[chuting1]

UP一下