Iphone 将NSData替换为特定NSStrting格式

我收到一份NSData，其中包含以下给出的六个值

   <aaaaaaa aaaaaab>

请帮助我如何获取上述格式，请帮助您可以尝试：

str = [str stringByReplacingOccurrencesOfString:@":"
                                     withString:@""];

str = [str lowercaseString];

str = @"<aaaaaaa aaaaaab>";
str = [str stringByReplacingOccurrencesOfString:@"<" withString:@""]; //Remove <
str = [str stringByReplacingOccurrencesOfString:@" " withString:@""]; //Remove space
str = [str stringByReplacingOccurrencesOfString:@">" withString:@""]; //Remove >
NSMutableString *mStr = [[NSMutableString alloc] initWithString:str];

for (int i=2; i< [mStr length]; i+=3) {
    [mStr insertString:@":" atIndex:i];
}
for (int i=11; i< [mStr length]; i+=12) {
    [mStr insertString:@" " atIndex:i];
}

str=@”；
str=[str STRINGBYREPLACINGOURCRENCESOFSTRING:@“with string:@]”//删除>
NSMutableString*mStr=[[NSMutableString alloc]initWithString:str]；
对于（int i=2；i<[mStr长度]；i+=3）{
[mStr insertString:@:“atidex:i]；
}
对于（int i=11；i<[mStr长度]；i+=12）{
[mStr insertString:@“atIndex:i]；
}

---

这将删除空格。然后添加：和空格。

您是要将NSData解码为NSString，还是将实际数据转换为字符串格式？我需要AA:AA:AA:AA:AA:AA:AB此格式

str = @"<aaaaaaa aaaaaab>";
str = [str stringByReplacingOccurrencesOfString:@"<" withString:@""]; //Remove <
str = [str stringByReplacingOccurrencesOfString:@" " withString:@""]; //Remove space
str = [str stringByReplacingOccurrencesOfString:@">" withString:@""]; //Remove >
NSMutableString *mStr = [[NSMutableString alloc] initWithString:str];

for (int i=2; i< [mStr length]; i+=3) {
    [mStr insertString:@":" atIndex:i];
}
for (int i=11; i< [mStr length]; i+=12) {
    [mStr insertString:@" " atIndex:i];
}