处理对象
处理对象
在Windows编程中，HANDLE根据不同的对象有不同的返回值，例如普通处理对象的无效值是NULL、
文件处理对象的无效值是INVALID_HANDLE_VALUE。
现对HANDLE进行封装，方便使用和扩展。
头文件
#pragma once
class CNullHandle
{
public:
CNullHandle(HANDLE h = NULL);
~CNullHandle();
void operator = (HANDLE h);
void Attach(HANDLE h);
void Close();
BOOL IsNull() const;
operator HANDLE () const;
public:
HANDLE m_handle;
};
class CInvalidHandle
{
public:
CInvalidHandle(HANDLE h = INVALID_HANDLE_VALUE);
~CInvalidHandle();
void operator = (HANDLE h);
void Attach(HANDLE h);
void Close();
BOOL IsNull() const;
operator HANDLE () const;
public:
HANDLE m_handle;
};
template<class T>
class CWinHandle
{
public:
CWinHandle(T h = NULL)
:m_h(h)
{
}
~CWinHandle()
{
}
void operator = (HANDLE h)
{
m_h = h;
}
void Attach(HANDLE h)
{
m_h.Attach(h);
}
void Close()
{
m_h.Close();
}
BOOL IsNull() const
{
return m_h.IsNull();
}
operator HANDLE () const
{
return m_h;
}
private:
T m_h;
};
实现文件
#include “stdafx.h”
#include “WinHandle.h”
CNullHandle::CNullHandle(HANDLE h/* = NULL*/)
:m_handle(h)
{
}
CNullHandle::~CNullHandle()
{
Close();
}
void CNullHandle::operator = (HANDLE h)
{
Attach(h);
}
void CNullHandle::Attach(HANDLE h)
{
if (NULL != m_handle && m_handle != h)
{
CloseHandle(m_handle);
m_handle = h;
}
}
void CNullHandle::Close()
{
if (NULL != m_handle)
{
CloseHandle(m_handle);
m_handle = NULL;
}
}
BOOL CNullHandle::IsNull() const
{
return (NULL == m_handle);
}
CNullHandle::operator HANDLE () const
{
return m_handle;
}
CInvalidHandle::CInvalidHandle(HANDLE h/* = INVALID_HANDLE_VALUE*/)
:m_handle(h)
{
}
CInvalidHandle::~CInvalidHandle()
{
Close();
}
void CInvalidHandle::operator = (HANDLE h)
{
Attach(h);
}
void CInvalidHandle::Attach(HANDLE h)
{
if (INVALID_HANDLE_VALUE != m_handle && m_handle != h)
{
CloseHandle(m_handle);
m_handle = h;
}
}
void CInvalidHandle::Close()
{
if (INVALID_HANDLE_VALUE != m_handle)
{
CloseHandle(m_handle);
m_handle = INVALID_HANDLE_VALUE;
}
}
BOOL CInvalidHandle::IsNull() const
{
return (INVALID_HANDLE_VALUE == m_handle);
}
CInvalidHandle::operator HANDLE () const
{
return m_handle;
}