字符串转16进制 16进制转字符串

测试网站 http://www.bejson.com/convert/ox2str/

//e8afb7e58187e58d95313532373836e8bf98e8819ae9a490666a68676a736a6a646a64
//请假单152786还聚餐fjhgjsjjdjd


//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; 
}


// 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];
        [scanner scanHexInt:&anInt];
        myBuffer[i / 2] = (char)anInt;
    }
    NSString *unicodeString = [NSString stringWithCString:myBuffer encoding:4];
    NSLog(@"------字符串=======%@",unicodeString);
    return unicodeString;
}

16进制转NSData NSData转16进制

// 16进制转NSData
- (NSData *)convertHexStrToData:(NSString *)str
{
    if (!str || [str length] == 0) {
        return nil;
    }
    
    NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:20];
    NSRange range;
    if ([str length] % 2 == 0) {
        range = NSMakeRange(0, 2);
    } else {
        range = NSMakeRange(0, 1);
    }
    for (NSInteger i = range.location; i < [str length]; i += 2) {
        unsigned int anInt;
        NSString *hexCharStr = [str substringWithRange:range];
        NSScanner *scanner = [[NSScanner alloc] initWithString:hexCharStr];
        
        [scanner scanHexInt:&anInt];
        NSData *entity = [[NSData alloc] initWithBytes:&anInt length:1];
        [hexData appendData:entity];
        
        range.location += range.length;
        range.length = 2;
    }
    return hexData;
}

 // NSData转16进制 第一种
- (NSString *)convertDataToHexStr:(NSData *)data
{
    if (!data || [data length] == 0) {
        return @"";
    }
    NSMutableString *string = [[NSMutableString alloc] initWithCapacity:[data length]];
    
    [data enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
        unsigned char *dataBytes = (unsigned char*)bytes;
        for (NSInteger i = 0; i < byteRange.length; i++) {
            NSString *hexStr = [NSString stringWithFormat:@"%x", (dataBytes[i]) & 0xff];
            if ([hexStr length] == 2) {
                [string appendString:hexStr];
            } else {
                [string appendFormat:@"0%@", hexStr];
            }
        }
    }];
    return string;
}


// NSData转16进制 第二种
-(NSString *)hexStringFormData:(NSData *)data
{
    return [[[[NSString stringWithFormat:@"%@",data]
            stringByReplacingOccurrencesOfString:@"<" withString:@""]
            stringByReplacingOccurrencesOfString:@">" withString:@""]
            stringByReplacingOccurrencesOfString:@" " withString:@""];
    
    

}

问题

• 在bejson网站测试的 换行的字符串 转成的 16进制进制

16进制到文本字符串的转换
换行
在线实时转换

用网站转成

3136e8bf9be588b6e588b0e69687e69cace5ad97e7aca6e4b8b2e79a84e8bdace68da2ae68da2e8a18cae59ca8e7babfe5ae9ee697b6e8bdace68da2

用代码 stringFromHexString不能把这个16进制再转回来

• 在代码设置 \n换行 是可以识别 并转换的

16进制到文本字符串的转换\n换行\n在线实时转换

用代码hexStringFromString 转成

3136e8bf9be588b6e588b0e69687e69cace5ad97e7aca6e4b8b2e79a84e8bdace68da20ae68da2e8a18c0ae59ca8e7babfe5ae9ee697b6e8bdace68da2

用代码stringFromHexString回转

16进制到文本字符串的转换
换行
在线实时转换

• 分析对照下

发现之所以转不过来,是因为换行符不一样 a 与 0a

3136e8bf9be588b6e588b0e69687e69cace5ad97e7aca6e4b8b2e79a84e8bdace68da2
a
e68da2e8a18c
a
e59ca8e7babfe5ae9ee697b6e8bdace68da2

3136e8bf9be588b6e588b0e69687e69cace5ad97e7aca6e4b8b2e79a84e8bdace68da2
0a
e68da2e8a18c
0a
e59ca8e7babfe5ae9ee697b6e8bdace68da2

中文字符串转NSData GBK 和 UTF-8

NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
NSData *valData = [hextext dataUsingEncoding:enc];

待补充