本文记录的是使用OC进行NSData和十六进制字符串之间的相互转换。其中将十六进制字符串转换成NSData的代码如下:
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| - (NSData *)convertHexStrToData:(NSString *)str { if (!str || [str length] == 0) { return nil; } NSMutableData *hexData = [[NSMutableData alloc] initWithCapacity:8]; 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; } LEDEBUG(@"hexdata: %@", hexData); return hexData; }
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如果传入参数 str
为 1ff
, 则hexdata
打印出:hexdata: <01ff>
将NSData转换成十六进制的字符串则可使用如下方式:
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| - (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; }
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将第一个例子中生成的NSData当做入参,则返回的string为01ff
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