字符串转码UTF8转码为GBK的C语言程序源代码

GBK和UTF8之间的转换可以使用MultiByteToWideChar和WideCharToMultiByte两个API，方法是先把它们转换为中间编码Unicode，再转换为对应的编码即可。

#include <stdio.h>

#include <windows.h>

//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;

}

// UTF8编码转换到GBK编码

int UTF8ToGBK(unsigned char * lpUTF8Str,unsigned char * lpGBKStr,int nGBKStrLen)

{

wchar_t * lpUnicodeStr = NULL;

int nRetLen = 0;

if(!lpUTF8Str) //如果UTF8字符串为NULL则出错退出

return 0;

nRetLen = ::MultiByteToWideChar(CP_UTF8,0,(char *)lpUTF8Str,-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_UTF8,0,(char *)lpUTF8Str,-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_ACP,0,lpUnicodeStr,-1,NULL,NULL,NULL,NULL); //获取转换到GBK编码后所需要的字符空间长度

if(!lpGBKStr) //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(nGBKStrLen < nRetLen) //如果输出缓冲区长度不够则退出

{

if(lpUnicodeStr)

delete []lpUnicodeStr;

return 0;

}

nRetLen = ::WideCharToMultiByte(CP_ACP,0,lpUnicodeStr,-1,(char *)lpGBKStr,nRetLen,NULL,NULL); //转换到GBK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:GBK转UTF8.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

nRetLen = UTF8ToGBK((unsigned char *)lpUTF8Str,NULL,NULL); //再转回来

printf("转换后的字符串需要的空间长度为：%d ",nRetLen);

lpGBKStr = new char[nRetLen + 1];

nRetLen = UTF8ToGBK((unsigned char *)lpUTF8Str,(unsigned char *)lpGBKStr,nRetLen);

if(nRetLen)

{

printf("UTF8ToGBK转换成功！ ");

}

else

{

printf("UTF8ToGBK转换失败！ ");

goto Ret0;

}

fp = fopen("C:UTF8转GBK.txt","wb"); //保存到文本文件

fwrite(lpGBKStr,nRetLen,1,fp);

fclose(fp);

getchar(); //再去打开文本文件看看，发现编码框又变为了“ANSI”说明转换成功了

Ret0:

if(lpGBKStr)

delete []lpGBKStr;

if(lpUTF8Str)

delete []lpUTF8Str;

return 0;

}