用C⼀C++写一个字符串GBK转UTF-8编码的函数，并写main函数测试(在线等)

VC6下编译通过， 转化后的文本文档在C盘目录下，你打开后点"文件"-> "另存为"，可看到编码类型为"UTF-8",说明转换成功了。还有什么不懂的再问我好了。多给我加分哦！呵呵

#include
#include

//GBK编码转换到UTF8编码
int GBKToUTF8(unsigned char * lpGBKStr,unsigned char * lpUTF8Str,int nUTF8StrLen)
{
wchar_t * lpUnicodeStr = NULL;
int nRetLen = 0;

if(!lpGBKStr) //如果GBK字符串为NULL则出错退出
return 0;

nRetLen = ::MultiByteToWideChar(CP_ACP,0,(char *)lpGBKStr,-1,NULL,NULL); //获取转换到Unicode编码后所需要的字符空间长度
lpUnicodeStr = new WCHAR[nRetLen + 1]; //为Unicode字符串空间
nRetLen = ::MultiByteToWideChar(CP_ACP,0,(char *)lpGBKStr,-1,lpUnicodeStr,nRetLen); //转换到Unicode编码
if(!nRetLen) //转换失败则出错退出
return 0;

nRetLen = ::WideCharToMultiByte(CP_UTF8,0,lpUnicodeStr,-1,NULL,0,NULL,NULL); //获取转换到UTF8编码后所需要的字符空间长度

if(!lpUTF8Str) //输出缓冲区为空则返回转换后需要的空间大小
{
if(lpUnicodeStr)
delete []lpUnicodeStr;
return nRetLen;
}

if(nUTF8StrLen < nRetLen) //如果输出缓冲区长度不够则退出
{
if(lpUnicodeStr)
delete []lpUnicodeStr;
return 0;
}

nRetLen = ::WideCharToMultiByte(CP_UTF8,0,lpUnicodeStr,-1,(char *)lpUTF8Str,nUTF8StrLen,NULL,NULL); //转换到UTF8编码

if(lpUnicodeStr)
delete []lpUnicodeStr;

return nRetLen;
}

//使用这两个函数的例子
int main()
{
char cGBKStr[] = "我是中国人!";
char * lpGBKStr = NULL;
char * lpUTF8Str = NULL;
FILE * fp = NULL;
int nRetLen = 0;

nRetLen = GBKToUTF8((unsigned char *) cGBKStr,NULL,NULL);
printf("转换后的字符串需要的空间长度为：%d ",nRetLen);
lpUTF8Str = new char[nRetLen + 1];
nRetLen = GBKToUTF8((unsigned char *)cGBKStr,(unsigned char *)lpUTF8Str,nRetLen);
if(nRetLen)
{
printf("GBKToUTF8转换成功！");
}
else
{
printf("GBKToUTF8转换失败！");
goto Ret0;
}
fp = fopen("C:\\GBKtoUTF8.txt","wb"); //保存到文本文件
fwrite(lpUTF8Str,nRetLen,1,fp);
fclose(fp);
getchar(); //先去打开那个文本文件看看，单击记事本的“文件”-“另存为”菜单，在对话框中看到编码框变为了“UTF-8”说明转换成功了

Ret0:

{
if(lpGBKStr)
delete []lpGBKStr;
if(lpUTF8Str)
delete []lpUTF8Str;
}
return 0;
}

look at this:

http://www.diybl.com/course/3_program/c++/cppsl/2008320/105871.html

and

http://www.cppblog.com/zgysx/articles/13085.html?opt=admin