Binary转换成Hex字符串

　　想调优别人的代码，网上搜索一下Binary to Hexstring的转换，全是利用printf、scanf之类实现的，效率好低，还是自己想个简单的办法吧！

.......此处省略一万字.......

改进后的方法：

 1 int tohex(void* str, int strlen, char *ascii, int size)
 2 {
 3     if(strlen == 0|| str== NULL || ascii==NULL)
 4     {
 5         if(NULL != ascii)
 6             ascii[0]=0x00;
 7         return 0;
 8     }
 9 
10      char* p1 = ascii;//new  char[len*2+1];
11     unsigned char* p2 = (unsigned char*)str;
12     int i = 0, j = 0;
13     char dict[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
14     bool blCuted = false;
15     for( i = 0; i < strlen; ++i)
16     {
17         p1[j] = dict[ (p2[i] >> 4)];
18         p1[j+1] = dict[p2[i] & 0x0F];
19         j+=2;
20 
21         if(j > size){
22             blCuted = true;
23             break;
24         }
25     }
26     if(blCuted)
27         j-=2 ;
28     p1[j]  =0x00;
29     return j;
30 }

改进前的方法（抄的）：

 1 int BCD2ASC(const char *str, int strlen,char *ascii, int size)
 2 {
 3     int    i = 0, p = 0, l = 0;
 4     byte ch;
 5 
 6     if(strlen == 0|| str== NULL || ascii==NULL)
 7         return NULL;
 8 
 9     bool blCuted = false;
10     while(i<strlen)
11     {
12         ch = str[i++];
13         l += 2;
14         if(l > size){
15             blCuted = true;
16             break;
17         }
18         p += sprintf(ascii+p, "%02X", ch);
19     }
20 
21     if(blCuted)
22         l-=2 ;
23     return l;
24 }

View Code

测试代码：

 1  int main( ) 
 2   {
 3       int a=0x1234;
 4       int b=0xabcd;
 5       char *bistr="x12x34x56x78x90xabxcdxefxe1xf9x1fx1ex00";
 6       char szTmp[1024*10] = {0};
 7  tohex(&a, sizeof(int),  szTmp, sizeof(szTmp)); cout << szTmp << endl;
 8     tohex(&b, sizeof(int),  szTmp, sizeof(szTmp)); cout << szTmp << endl;
 9      tohex(bistr, strlen(bistr),  szTmp, sizeof(szTmp)); cout << szTmp << endl;
10 
11      FILE* fp = fopen("D:\testbinary.bi", "rb");
12      char szBinary[1024*5] = {0};
13      int ired = fread(szBinary, 1, 1024*5-1, fp);
14      cout << "readlen:" << ired <<endl;
15 
16      DWORD dwB = GetTickCount();
17      for(int i = 0; i < 1; ++i) 
18      {
19          tohex(szBinary, ired, szTmp, sizeof(szTmp)-1024); //i=1w,<200ms
20          cout << szTmp << endl;
21          BCD2ASC(szBinary, ired, szTmp, sizeof(szTmp)-1024); //i=1w,9000ms
22          cout << szTmp << endl;
23      }
24      DWORD dwE = GetTickCount();
25 
26      cout << "cost:" << dwE-dwB << "ms" <<endl;
27 
28      fclose(fp);
29      return 0;
30 }

View Code

效率差的不是一条街，你可以try一下。