字符编码问题

Windows API 函数
MessageBoxA:MessageBox 内部实现，字符串编码(ANSI)转换成了Unicode,在调用MessageboxW
MessageBox:是一个宏定义
MessageBoxA(NULL,"Hello","提示",MB_OK);
MessageBoxW(NULL,L"Hello",L"提示",MB_OK);

编码转换问题

ANSI转Unicode

//ANSI转Unicode
wchar_t* CCharset::AnsiToUnicode(const char* str)
{
	if (m_wstr)//安全
	{
		delete m_wstr;
		m_wstr = NULL;
	}
		
	DWORD dwSize=::MultiByteToWideChar(CP_ACP,0,str,-1,NULL,0);//求宽字符的大小
	m_wstr = new wchar_t[dwSize];
	::MultiByteToWideChar(CP_ACP, 0, str, -1, m_wstr, dwSize);
	return m_wstr;
}

Unicode转ANSI

//Unicode转ANSI
char * CCharset::UnicodeToAnsi(const wchar_t * wstr)
{
	if (m_str)
	{
		delete m_str;
		m_str = NULL;
	}
	DWORD dwSize=WideCharToMultiByte(CP_ACP, 0, wstr, -1,NULL,0,NULL,NULL);
	m_str = new char[dwSize];
	::WideCharToMultiByte(CP_ACP, 0, wstr, -1, m_str, dwSize, NULL, NULL);
	return m_str;
}

Utf8转 ANSI

char * CCharset::Utf8ToAnsi(const char * str)
{
	if (m_wstr)
	{
		delete[] m_wstr;
		m_wstr = NULL;
	}

	if (m_str)
	{
		delete[] m_str;
		m_str = NULL;
	}
	//UTF-8 转Unicode
	m_wstr= Utf8ToUnicode(str);
	//Unicode 转ANSI
	m_str= UnicodeToAnsi(m_wstr);
	return m_str;
}

utf8 转Unicode

wchar_t* CCharset::Utf8ToUnicode(const char * str)
{
	if (m_wstr)
	{
		delete m_wstr;
		m_wstr = NULL;
	}
	DWORD dwSize=MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
	m_wstr = new wchar_t[dwSize];
	memset(m_wstr, 0, dwSize*sizeof(wchar_t));//清空内存
	MultiByteToWideChar(CP_UTF8, 0, str, -1, m_wstr, dwSize);
	return m_wstr;
}

ANSI 转UTF-8

char* CCharset::AnsitoUtf8(const char* str)
{
	if (m_wstr)
	{
		delete[] m_wstr;
		m_wstr = NULL;
	}

	if (m_utf8)
	{
		delete[] m_utf8;
		m_utf8 = NULL;
	}

	//Ansi 转Unicode
	m_wstr= AnsiToUnicode(str);
	//Unicode 转UTF-8
	m_utf8=UnicodeToUtf8(m_wstr);

	return m_utf8;
}

Unicode 转 UTF-8

char * CCharset::UnicodeToUtf8(const wchar_t * wstr)
{
	if (m_utf8)
	{
		delete[] m_utf8;
		m_utf8 = NULL;
	}
	DWORD dwSize=WideCharToMultiByte(CP_UTF8, 0, wstr, -1, NULL, 0, NULL, NULL);
	m_utf8 = new char[dwSize];
	memset(m_utf8,0,dwSize);//清空内存
	WideCharToMultiByte(CP_UTF8, 0, wstr, -1, m_utf8, dwSize, NULL, NULL);
	return m_utf8;
}

全部代码

CCharset.h

#pragma once
class CCharset
{

private:
	wchar_t* m_wstr;
	char* m_str;
	char* m_utf8;
public:
	CCharset();
	~CCharset();

	//ANSI转Unicode
	wchar_t* AnsiToUnicode(const char* str);
	//Unicode转ANSI
	char* UnicodeToAnsi(const wchar_t* wstr);
	//UTF8 转ANSI
	char* Utf8ToAnsi(const char* str);
	//ANSI转UTF - 8
	char* AnsitoUtf8(const char* str);
	//Unicode 转 UTF-8
	char* UnicodeToUtf8(const wchar_t* wstr);
	//UTF-8转Unicode
	wchar_t* Utf8ToUnicode(const char* str);

};

CCharset.cpp

#include "pch.h"
#include "CCharset.h"

CCharset::CCharset()
{
	m_wstr = NULL;
	m_str = NULL;
	m_utf8 = NULL;
}


CCharset::~CCharset()
{
	if (m_wstr)
	{
		delete m_wstr;
		m_wstr = NULL;
	}
		
	if (m_str)
	{
		delete m_str;
		m_str = NULL;
	}

	if (m_utf8)
	{
		delete[] m_utf8;
		m_utf8 = NULL;
	}
}

//ANSI转Unicode
wchar_t* CCharset::AnsiToUnicode(const char* str)
{
	if (m_wstr)//安全
	{
		delete[] m_wstr;
		m_wstr = NULL;
	}
		
	DWORD dwSize=::MultiByteToWideChar(CP_ACP,0,str,-1,NULL,0);//求宽字符的大小
	m_wstr = new wchar_t[dwSize];
	::MultiByteToWideChar(CP_ACP, 0, str, -1, m_wstr, dwSize);
	return m_wstr;
}

//Unicode转ANSI
char * CCharset::UnicodeToAnsi(const wchar_t * wstr)
{
	if (m_str)
	{
		delete[] m_str;
		m_str = NULL;
	}
	DWORD dwSize=WideCharToMultiByte(CP_ACP, 0, wstr, -1,NULL,0,NULL,NULL);//求字符的大小
	m_str = new char[dwSize];
	::WideCharToMultiByte(CP_ACP, 0, wstr, -1, m_str, dwSize, NULL, NULL);
	return m_str;
}


char * CCharset::Utf8ToAnsi(const char * str)
{
	if (m_wstr)
	{
		delete[] m_wstr;
		m_wstr = NULL;
	}

	if (m_str)
	{
		delete[] m_str;
		m_str = NULL;
	}
	//UTF-8 转Unicode
	m_wstr= Utf8ToUnicode(str);
	//Unicode 转ANSI
	m_str= UnicodeToAnsi(m_wstr);
	return m_str;
}

char* CCharset::AnsitoUtf8(const char* str)
{
	if (m_wstr)
	{
		delete[] m_wstr;
		m_wstr = NULL;
	}

	if (m_utf8)
	{
		delete[] m_utf8;
		m_utf8 = NULL;
	}

	//Ansi 转Unicode
	m_wstr= AnsiToUnicode(str);
	//Unicode 转UTF-8
	m_utf8=UnicodeToUtf8(m_wstr);

	return m_utf8;
}

//Unicode 转 UTF-8
char * CCharset::UnicodeToUtf8(const wchar_t * wstr)
{
	if (m_utf8)
	{
		delete[] m_utf8;
		m_utf8 = NULL;
	}
	DWORD dwSize=WideCharToMultiByte(CP_UTF8, 0, wstr, -1, NULL, 0, NULL, NULL);
	m_utf8 = new char[dwSize];
	memset(m_utf8,0,dwSize);//清空内存
	WideCharToMultiByte(CP_UTF8, 0, wstr, -1, m_utf8, dwSize, NULL, NULL);
	return m_utf8;
}

//utf8 转Unicode
wchar_t* CCharset::Utf8ToUnicode(const char * str)
{
	if (m_wstr)
	{
		delete m_wstr;
		m_wstr = NULL;
	}
	DWORD dwSize=MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
	m_wstr = new wchar_t[dwSize];
	memset(m_wstr, 0, dwSize*sizeof(wchar_t));//清空内存
	MultiByteToWideChar(CP_UTF8, 0, str, -1, m_wstr, dwSize);
	return m_wstr;
}