怎样把CString转换成_variant_t？

[lllhaier]

1.在ado操作中，怎么样把CString转换成_variant_t？请给出例子，谢谢!

2.

CString s;
LPTSTR temp=(LPTSTR)(LPCTSTR)s;
以上两句运行时出错，跟踪进去到此处：
_AFX_INLINE CString::operator LPCTSTR() const
{ return m_pchData; }
请问是怎么回事？

[huanyun]

_variant_t vt(str);
LPTSTR temp=s.getbuffer(0);

[lwugui]

_variant_t limiturl;
limiturl= m_pURLRecordset->GetCollect("limurl");
CString url = (LPCTSTR)(_bstr_t)limiturl;

[lwugui]

LPTSTR lpszText;
strcpy(lpszText,"Test");

[lwugui]

LPTSTR lpType;
CString m_strFileName;
CString strTmp;
strTmp = m_strFileName.Right(3); //从右取3个
lpType = LPCTSTR(strTmp); //强制转换

[commandconque]

完全写法：
VARIANT varValue;
CString va;
varValue->vt=VT_BSTR;
varValue->bstrVal=(_bstr_t)var;

[dhbo]

赞同楼上bluebohe(薄荷) ：
CString str="sdafkljjksafd";
_variant_t str1((LPCTSTR)str);

[bluebohe]

1:
CString str="sdafkljjksafd";
_variant_t str1((LPCTSTR)str);
2:
如果仅仅是这么两句就出问题的话，应该是你的s没有初始化的缘故

[yyfa6]

赞同bluebohe(薄荷)

[weixxxp]

1.
CString value;
_variant_t vt;
vt.vt = value.IsEmpty() ? VT_NULL : VT_BSTR;
vt.bstrVal = value.AllocSysString();

[GreenHeart]

试试这个函数
ConstructVar(CString StrValue, int type, VARIANT *var)
{
COleDateTime var_date;
CURRENCY cy;
cy.Hi = 0;
switch (type)
{
case adInteger:
var->vt = VT_I4;
var->lVal = atoi(StrValue);
break;
case adChar:
case adVarWChar:
var->vt = VT_BSTR;
var->bstrVal = (_bstr_t)StrValue;
break;
case adDBTimeStamp:
var->vt = VT_DATE;
var->date = var_date;
default:
var->vt = VT_EMPTY;
break;
}
return TRUE;
}

[weixxxp]

2.CString::operator LPCTSTR() 返回的是const指针，当然不能再(LPTSTR)了，直接用GetBuffer(0)就可以了。

[zhaolaoxin]

COleVariant newvalue;
CString strtmp;
strtmp = "abcdefg";
newvalue.SetString(strtmp, VT_BSTR);

[dy_paradise]

CString s1;
s1.Format("%s",(char *)bstr);

[dy_paradise]

没有必要那么麻烦吧

[windyhui]

CString str;
_variant_t(str);

[woolgate]

下载一个ADOClass,
使用方法New一个CADODatabase,再New一个CADORecordset,
然后就用吧 :)
用ADO简直方便死掉了。

http://www.codeproject.com/database/CAAAdoClass1/AdoClass_src.zip

[xiaohedou]

look ^ study

[漂行者]

CString str;
_variant_t _vl;
_vl=(_variant_t)(LPCTSTR)str;

[Viconia]

直接强制转换

vl=(_variant_t)(LPCTSTR)str;