无效指针问题

2011-01-09 07:09:12 224 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

c++ mysql_init 返回无效指针_C++操作MYSQL遇到的一些问题首先我使用的是 vcpkg上面是我装的一些库《大大安利vcpkg 安装时一定要使用powershell进行编译装上vcpkg后装ligmariadb这个库，这个对Mysql操作还是挺方便的，然后说一下在装库时碰到的一些问题1.网络问题1.参考了一下 github上的答案将下载失败的url拷下来自己下然后再重新开始安装《vcpkg在安装时每一个需要下载的都会提供url-仔细找，2.这个问... 阅读详情

我用ado连接数据库，做了两个子函数，两个函数里面都定义了RecordSet对象，分别连接同一数据库文件下的不同表，一起先后调用时就会出现错误，但只是单独调用时就没问题，错误都为无效指针，请问这是为什么
PROGRAM TEST
INTERFACE
SUBROUTINE DataInput2(t,a,b) !申明结点坐标数据输入函数
!DEC$ATTRIBUTES C,ALIAS:'_DataInput2'::DataInput2
INTEGER(4)::t
real(4)::a[reference]
real(4)::b[reference]
END SUBROUTINE
SUBROUTINE DataInput1(k,a,b,c,d) !申明单元结点数据输入函数
!DEC$ATTRIBUTES C,ALIAS:'_DataInput1'::DataInput1
INTEGER(4)::k
INTEGER(4)::a[reference]
INTEGER(4)::b[reference]
INTEGER(4)::c[reference]
INTEGER(4)::d[reference]
END SUBROUTINE

END INTERFACE
real a,b
integer c,d,e,f
call DataInput1(3,c,d,e,f)
call DataInput2(4,a,b)
write(*,*) a,b,c,d,e,f
end

#import "c:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")
#include <stdio.h>
#include <icrsint.h>

class CCustomRs : public CADORecordBinding
{
BEGIN_ADO_BINDING(CCustomRs)
ADO_NUMERIC_ENTRY(1,adInteger,a[0],1,0,m_ul_fnameStatus1,true)
ADO_NUMERIC_ENTRY(2,adInteger,a[1],1,0,m_ul_fnameStatus2,true)
ADO_NUMERIC_ENTRY(3,adInteger,a[2],1,0,m_ul_fnameStatus3,true)
ADO_NUMERIC_ENTRY(4,adInteger,a[3],1,0,m_ul_fnameStatus3,true)

END_ADO_BINDING()

public:
int a[4];
ULONG m_ul_fnameStatus1;
ULONG m_ul_fnameStatus2;
ULONG m_ul_fnameStatus3;
ULONG m_ul_fnameStatus4;
};

inline void TESTHR(HRESULT _hr)
{ if FAILED(_hr) _com_issue_error(_hr); }
extern"C"void DataInput1(int k,int& a,int& b,int& c,int& d)
{
_COM_SMARTPTR_TYPEDEF(IADORecordBinding, __uuidof(IADORecordBinding));

::CoInitialize(NULL);
try
{
_RecordsetPtr pRs("ADODB.Recordset");
CCustomRs rs;
IADORecordBindingPtr picRs(pRs);
pRs->Open("SELECT * FROM 单元结点",
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=二维有压渗流数据.mdb",
adOpenStatic, adLockOptimistic, adCmdText);
TESTHR(picRs->BindToRecordset(&rs));
pRs->AbsolutePosition=(PositionEnum)k;
a=rs.a[0];
b=rs.a[1];
c=rs.a[2];
d=rs.a[3];
pRs->Close();
}
catch (_com_error &e)
{
printf("Error:\n");
printf("Code = %08lx\n", e.Error());
printf("Meaning = %s\n", e.ErrorMessage());
printf("Source = %s\n", (LPCSTR) e.Source());
printf("Description = %s\n", (LPCSTR) e.Description());
}
::CoUninitialize();
}

#import "c:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")
#include <stdio.h>
#include <icrsint.h>
class CCustomRs : public CADORecordBinding
{
BEGIN_ADO_BINDING(CCustomRs)
ADO_NUMERIC_ENTRY(2,adSingle,a[1],0.00001,0,m_ul_fnameStatus2,true)
ADO_NUMERIC_ENTRY(3,adSingle,a[2],0.00001,0,m_ul_fnameStatus3,true)
END_ADO_BINDING()

public:
float a[3];
ULONG m_ul_fnameStatus2;
ULONG m_ul_fnameStatus3;

};

inline void TESTHR(HRESULT _hr)
{ if FAILED(_hr) _com_issue_error(_hr); }

extern"C"void DataInput2(int t,float& b,float& c)
{
_COM_SMARTPTR_TYPEDEF(IADORecordBinding, __uuidof(IADORecordBinding));
::CoInitialize(NULL);
try
{
_RecordsetPtr pRs("ADODB.Recordset");
CCustomRs rs;
int i;
IADORecordBindingPtr picRs(pRs);
pRs->Open("SELECT * FROM 坐标",
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=二维有压渗流数据.mdb",
adOpenStatic, adLockOptimistic, adCmdText);
TESTHR(picRs->BindToRecordset(&rs));
pRs->AbsolutePosition=(PositionEnum)t;
b=rs.a[1];
c=rs.a[2];

}
catch (_com_error &e) {
printf("Error:\n");
printf("Code = %08lx\n", e.Error());
printf("Meaning = %s\n", e.ErrorMessage());
printf("Source = %s\n", (LPCSTR) e.Source());
printf("Description = %s\n", (LPCSTR) e.Description());
}
::CoUninitialize();
}

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