iOS十六进制和字符串的相互转换

    NSString *dictString = [dict JSONFragment];//组合成的。 

用这个就行了。。。

    dictString==={"content":"Sadgfdfg","phoneno":"","email":"[email protected]"}=== 

    // 十六进制转换为普通字符串的。
    + (NSString *)stringFromHexString:(NSString *)hexString { // 

    char *myBuffer = (char *)malloc((int)[hexString length] / 2 + 1);
    bzero(myBuffer, [hexString length] / 2 + 1);
    for (int i = 0; i < [hexString length] - 1; i += 2) {
    unsigned int anInt;
    NSString * hexCharStr = [hexString substringWithRange:NSMakeRange(i, 2)];
    NSScanner * scanner = [[[NSScanner alloc] initWithString:hexCharStr] autorelease];
    [scanner scanHexInt:&anInt];
    myBuffer[i / 2] = (char)anInt;
    }
    NSString *unicodeString = [NSString stringWithCString:myBuffer encoding:4];
    NSLog(@"------字符串=======%@",unicodeString);
    return unicodeString; 

    } 

    //普通字符串转换为十六进制的。 

    + (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];
    }
    return hexStr;
    }