十六进制字符串 转 byte数组

目标字符串 NSString *str = @"0200107580FD7590FD75A0FD75B0FD22787FE4F6D8FD7581070200030200107580FD7590FD75A0FD";

转换后

 byte数组 Byte byteArr[] = { 0x02, 0x00, 0x10, ... ,  0xFD };

调用方法：NSData *temp = [string hexToBytes];

//十六进制字符串转换成字节数组

- (NSData *)hexToBytes

{

    NSMutableData *muData = [NSMutableData data];

    for (int i = 0; i + 2 <= self.length; i += 2)

    {

        NSRange range = NSMakeRange(i, 2);

        NSString *hexStr = [self substringWithRange:range];

        NSScanner *scanner = [NSScanner scannerWithString:hexStr];

        unsigned int intValue;

        [scanner scanHexInt:&intValue];

        [muData appendBytes:&intValue length:1];

    }

    return muData;

}