今天在代碼中看到下面一個函數：
CString CConnectManager::newGUID()
{
CString buf;
GUID guid;
if (S_OK == ::CoCreateGuid(&guid))
{
buf.Format("{%08X-%04X-%04x-%02X%02X-%02X%02X%02X%02X%02X%02X}"
, guid.Data1
, guid.Data2
, guid.Data3
, guid.Data4[0], guid.Data4[1]
, guid.Data4[2], guid.Data4[3], guid.Data4[4], guid.Data4[5]
, guid.Data4[6], guid.Data4[7]);
}
return buf;
}
用來返回一個系統自動生成的32位字符串。
關於CoCreateGuid()函數，MSDN如下解釋：
Creates a GUID, a unique 128-bit integer used for CLSIDs and interface identifiers.
HRESULT CoCreateGuid(
GUID * pguid
);
如果函數執行成功，返回S_OK，
GUID是一個結構體，MSDN解釋如下：
The GUID structure stores a GUID.
typedef struct _GUID {
DWORD Data1;
WORD Data2;
WORD Data3;
BYTE Data4[8]; } GUID;
Members
- Data1
-
Specifies the first 8 hexadecimal digits of the GUID.
- Data2
-
Specifies the first group of 4 hexadecimal digits.
- Data3
-
Specifies the second group of 4 hexadecimal digits.
- Data4
-
Array of 8 bytes. The first 2 bytes contain the third group of 4 hexadecimal digits. The remaining 6 bytes contain the final 12 hexadecimal digits.
Remarks
GUIDs are the Microsoft implementation of the distributed computing environment (DCE) universally unique identifier ( UUID). The RPC run-time libraries use UUIDs to check for compatibility between clients and servers and to select among multiple implementations of an interface. The Windows access-control functions use GUIDs to identify the type of object that an object-specific ACE in an access-control list (ACL) protects.
函數用來返回一個唯一的表示字符串。