CA2WEX Class
The latest version of this topic can be found at CA2WEX Class.
This class is used by the string conversion macros CA2TEX, CA2CTEX, CT2WEX, and CT2CWEX, and the typedef CA2W.
Important
This class and its members cannot be used in applications that execute in the Windows Runtime.
Syntax
template <int t_nBufferLength = 128>
class CA2WEX
Parameters
t_nBufferLength
The size of the buffer used in the translation process. The default length is 128 bytes.
Members
Public Constructors
| Name | Description |
|---|---|
| CA2WEX::CA2WEX | The constructor. |
| CA2WEX::~CA2WEX | The destructor. |
Public Operators
| Name | Description |
|---|---|
| CA2WEX::operator LPWSTR | Conversion operator. |
Public Data Members
| Name | Description |
|---|---|
| CA2WEX::m_psz | The data member that stores the source string. |
| CA2WEX::m_szBuffer | The static buffer, used to store the converted string. |
Remarks
Unless extra functionality is required, use CA2TEX, CA2CTEX, CT2WEX, CT2CWEX, or CA2W in your code.
This class contains a fixed-size static buffer which is used to store the result of the conversion. If the result is too large to fit into the static buffer, the class allocates memory using malloc, freeing the memory when the object goes out of scope. This ensures that, unlike text conversion macros available in previous versions of ATL, this class is safe to use in loops and that it won't overflow the stack.
If the class tries to allocate memory on the heap and fails, it will call AtlThrow with an argument of E_OUTOFMEMORY.
By default, the ATL conversion classes and macros use the current thread's ANSI code page for the conversion. If you want to override that behavior for a specific conversion, specify the code page as the second parameter to the constructor for the class.
The following macros are based on this class:
CA2TEXCA2CTEXCT2WEXCT2CWEX
The following typedef is based on this class:
- CA2W
For a discussion of these text conversion macros, see ATL and MFC String Conversion Macros.
Example
See ATL and MFC String Conversion Macros for an example of using these string conversion macros.
Requirements
Header: atlconv.h
CA2WEX::CA2WEX
The constructor.
CA2WEX(LPCSTR psz, UINT nCodePage) throw(...);
CA2WEX(LPCSTR psz) throw(...);
Parameters
psz
The text string to be converted.
nCodePage
The code page used to perform the conversion. See the code page parameter discussion for the Windows SDK function MultiByteToWideChar for more details.
Remarks
Allocates the buffer used in the translation process.
CA2WEX::~CA2WEX
The destructor.
~CA2WEX() throw();
Remarks
Frees the allocated buffer.
CA2WEX::m_psz
The data member that stores the source string.
LPWSTR m_psz;
CA2WEX::m_szBuffer
The static buffer, used to store the converted string.
wchar_t m_szBuffer[t_nBufferLength];
CA2WEX::operator LPWSTR
Conversion operator.
operator LPWSTR() const throw();
Return Value
Returns the text string as type LPWSTR.
See Also
CA2AEX Class
CA2CAEX Class
CW2AEX Class
CW2CWEX Class
CW2WEX Class
Class Overview