字符串与16进制的转换

//把字符串转换成十六进制字符串
+ (NSString *)hexStringFromString:(NSString *)string{
NSData *myD = [string
dataUsingEncoding:NSUTF8StringEncoding];
Byte *bytes = (Byte *)[myD
bytes];
//下面是Byte
转换为16进制。
NSString *hexStr=@"";
for(int i=0;i<[myD
length];i++){
NSString *newHexStr = [NSString
stringWithFormat:@"%x",bytes[i]&0xff];///16进制数
if([newHexStr
length]==1){
hexStr = [NSString
stringWithFormat:@"%@0%@",hexStr,newHexStr];
}
else{
hexStr = [NSString
stringWithFormat:@"%@%@",hexStr,newHexStr];
}
if (i != [myD
length] -1){
hexStr = [NSString
stringWithFormat:@"%@%@",hexStr,@"-"];
}
}
return hexStr;
}

//把一个十六进制拼成的字符串按分隔符分开，将每一个十六进制的值存到array中，返回长度

+(NSInteger)byteArrayFromHexString:(NSString *)string separater:(NSString *)separater
array:(Byte *)array
{

NSArray *hexArray = [string
componentsSeparatedByString:separater];
Byte *mac = array;
NSInteger count = hexArray.count;
for (int i =
0; i < count; i++)
{
@autoreleasepool {
NSString *s = [hexArray
objectAtIndex:i];
NSString *hexStr = [NSString
stringWithFormat:@"0x%@", s];
NSScanner *scanner = [NSScanner
scannerWithString:hexStr];
unsigned
int m = 0;
[scanner scanHexInt:&m];
*mac++ = m;
s = nil;
hexStr = nil;
scanner = nil;
}

}
hexArray = nil;
return count;
}