[C/C++]_[使用libiconv库转换字符编码]

场景：

1.在windows上我们可以通过WideCharToMultiByte和MultiByteToWideChar直接转换或间接转换编码,但是在linux或mac上却没有那么方便的系统api了，这时候可以使用libiconv库来进行转码，质量还是很高的。

2.以下我们把utf8编码字符串转换为utf16-le（小端序）编码。

文件test_iconv.cpp,是utf8编码。

#include 
  
   
#include 
   
     #include 
    
      #include "iconv.h" int GetUtf8LetterNumber(const char *s) { int i = 0, j = 0; while (s[i]) { if ((s[i] & 0xc0) != 0x80) j++; i++; } return j; } int main(int argc,char *argv[]) { iconv_t cd = NULL; cd = iconv_open("UTF-16LE", "UTF-8"); char *inptr = (char*)"我们的国家"; char* inptr1 = inptr; size_t length_i = strlen(inptr); printf("length_i %d\n",length_i); size_t length = GetUtf8LetterNumber(inptr)*2; size_t lengtht = length; printf("length %d\n",length); char* temp_dest = (char*)malloc(length+2); char* temp_destt = temp_dest; memset(temp_dest,0,length+2); size_t result = iconv(cd, &inptr1, &length_i, &temp_dest, &length); if (result != (size_t) -1) { iconv_close(cd); } printf("length %d\n",length); printf("length_i %d\n",length_i); for(int i = 0;i
     
      
 输出utf16-le的16进制编码. 
      
 
      





 
      
length_i 15
length 10
length 0
length_i 0
11
62
ec
4e
84
76
fd
56
b6
5b
      
 注意：参数length_i和length是递减的，这样原来的值会丢失，所以重新赋给新的值。 
      
 
      
 
      
size_t iconv (iconv_t cd,
              const char* * inbuf, size_t * inbytesleft,
              char* * outbuf, size_t * outbytesleft);
      
The iconv function converts one multibyte character at a time, and for each character conversion it increments *inbuf and
decrements *inbytesleft by the number of converted input bytes, it increments *outbuf and decrements *outbytesleft by the number 
of converted output bytes, and it updates the conversion state contained in cd.
看这里有iconv函数解释地址： 
      
 
      
http://www.gnu.org/savannah-checkouts/gnu/libiconv/documentation/libiconv-1.13/iconv.3.html
 
 
 
      
这里是支持的编解码列表：
 
      
http://www.gnu.org/savannah-checkouts/gnu/libiconv/documentation/libiconv-1.13/iconv_open.3.html