VB调用VC DLL 约定错误,求高手指点

VC函数是:extern "C" int __declspec(dllexport)PassPortRead(char *InPutData,char OuPutData[255]);
VB声明是：Private Declare Function PassPortRead Lib "PPRead.dll" (ByVal InPutData As String, ByVal OutPutData As String) As Integer
生成的文件能正常运行,并且能生成相应数据,但是在调试时提示"DLL调用约定错误"
E_Mail:linnda413@126.com
VC代码:
int PassPortRead(char *InPutData,char OutPutData[255])
{
 char tmp[255];
 int len = 0;
 memset(tmp,0,255);
 //初如化成员变量passInfo
 memset(PassInfo.Name,0,20);
 memset(PassInfo.Birth,0,20);
 memset(PassInfo.Gender,0,10);
 memset(PassInfo.Nationality,0,10);
 memset(PassInfo.Number,0,20);
 memset(PassInfo.IdCode,0,20);
 memset(PassInfo.Expiry,0,20);
 memset(PassInfo.CIssue,0,20);
 //删除换行与回车字符
 DelInStr(InPutData,"\r");
 DelInStr(InPutData,"\n");
 
 
 len = strlen(InPutData);
 if (len == 0)
 {
  return -1;
 }
 if (len < 80)
 {
  PassportParseTD2(InPutData); 
 }else{
  PassportParseTD1(InPutData); 
 } 
 sprintf(tmp,"#01%s#02%s#03%s#04%s#05%s#06%s#07%s#08%s",
  PassInfo.Name,PassInfo.Birth,PassInfo.Gender,PassInfo.Nationality,PassInfo.Number,
  PassInfo.IdCode,PassInfo.Expiry,PassInfo.CIssue);
 strcat(OutPutData,tmp);
 
 return 0;
}
VB代码:
Private Declare Function PassPortRead Lib "PPRead.dll" (ByVal InPutData As String, ByVal OutPutData As String) As Integer
Private Sub START_BTN_Click()
Dim PPData As String
Dim PPShow As String
PPData = PPData_TXT.Text
PPShow = String(255, vbNullChar)
If PPData = "" Then
    PRSHOW_TXT.Text = "护照数据不能为空..."
End If
Call PassPortRead(PPData, PPShow)
PRSHOW_TXT.Text = PPShow
End Sub
生成程序运行正常:
调试时出现错误