如何连接CComBSTR和字符串？

Question

如何连接CComBSTR和字符串？

我试过这种方式：

CComBSTR a = "DEF";
CComBSTR strRequete = "ABC'" + a + "GHI"; //marked line

但我在a的{​​{1}}告诉我

时收到错误

  

错误：表达式必须具有整数或未整合的枚举类型。

非常感谢！

Answer 1

要连接，您有8 methods：

HRESULT Append(LPCOLESTR lpsz, int nLen);             
HRESULT Append(LPCOLESTR lpsz);                       
HRESULT Append(LPCSTR);                               
HRESULT Append(char ch);                              
HRESULT Append(wchar_t ch);                           

HRESULT Append(const CComBSTR& bstrSrc);          
CComBSTR& operator+=(const CComBSTR& bstrSrc);

HRESULT AppendBSTR(BSTR p);  

使用+ =运算符，您可以这样追加：

CComBSTR strSentence = OLESTR("Now is the time ");

// strSentence contains "Now is the time "
CComBSTR str11 (OLESTR("for all good men ");
// calls Append(const CComBSTR& bstrSrc);
strSentence.Append(str11);
// strSentence contains "Now is the time for all good men "
// calls Append(LPCOLESTR lpsz);
strSentence.Append((OLESTR("to come "));
// strSentence contains "Now is the time for all good men to come "
// calls Append(LPCSTR lpsz);
strSentence.Append("to the aid ");
// strSentence contains
// "Now is the time for all good men to come to the aid "

CComBSTR str12 (OLESTR("of their country"));
strSentence += str12; // calls operator+=()
// "Now is the time for all good men to come to
// the aid of their country"

此链接提供了更多相关信息：http://www.369o.com/data/books/atl/0321159624/ch02lev1sec3.html

Answer 2

微软说：

CComBSTR类是BSTR的包装器，它是长度为前缀的字符串。

您必须使用CComBSTR::Append 或

  

bstr = CStringW（L＆＃34; String2＆＃34;）+ bstr

Refer to