字符串及处理之六: 转换实例_类字符串转实例-优快云博客

本文链接：https://blog.youkuaiyun.com/white_cpf/article/details/658764

本文详细介绍了不同字符串类型之间的转换方法，包括BSTR、CString、std::string等类型的使用技巧及注意事项，通过具体示例展示了如何在C++中进行有效的字符串管理和操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

字符串及类之间的转换方法

BSTR      bstr= NULL;
CString   cstr;
string    stlstr;
_bstr_t   bs1;

bstr = SysAllocString ( L"Hi Bob!" );
if ( NULL == bstr )
// out of memory error
// Use bstr here...
SysFreeString ( bstr );

// Extracting data
LPCSTR psz1 = bs1;              // automatically converts to MBCS string
LPCSTR psz2 = (LPCSTR) bs1;     // cast OK, same as previous line
LPCWSTR pwsz1 = bs1;            // returns the internal Unicode string
LPCWSTR pwsz2 = (LPCWSTR) bs1; // cast OK, same as previous line
BSTR    bstr = bs1.copy();      // copies bs1, returns it as a BSTR
SysFreeString ( bstr );      　　　　

LPCSTR psz = str.c_str(); // read-only pointer to str''s buffer
LPCWSTR pwsz = wstr.c_str(); // read-only pointer to wstr''s buffer
LPCTSTR ptsz = tstr.c_str(); // read-only pointer to tstr''s buffer

// Example, construct _bstr_t from basic_string
_bstr_t bs1 = str.c_str(); // construct a _bstr_t from a LPCSTR
_bstr_t bs2 = wstr.c_str(); // construct a _bstr_t from a LPCWSTR

BSTR bstr1 = bs1; // returns internal BSTR, but don''t modify it!
BSTR bstr2 = (BSTR) bs1; // cast ok, same as previous line
BSTR bstr3 = bs1.Copy(); // copies bs1, returns it as a BSTR
BSTR bstr4;
bstr4 = bs1.Detach(); // bs1 no longer manages its BSTR
// ...
SysFreeString ( bstr3 );
SysFreeString ( bstr4 );

CString s5 ( (LPCTSTR) IDS_SOME_STR ); // load from string table

// Converting to BSTR
CString s5 = "Bob!";
BSTR bs1 = NULL, bs2 = NULL;
bs1 = s5.AllocSysString();
s5.SetSysString ( &bs2 );
SysFreeString ( bs1 );
SysFreeString ( bs2 );