iOS BCD編碼

inline static NSData* encodeBCD(NSString *value){//NSString *value = @"123456";NSMutableData *vdata = [[NSMutableData alloc] init];__uint8_t bytes[1] = {6};[vdata appendBytes:&bytes length:1];NSRange range;range.location = 0;range.length = 1;for (int i = 0; i < [value length];) {range.location = i;NSString *temp = [value substringWithRange:range];int _intvalue1 = [temp intValue];_intvalue1 = _intvalue1 << 4;range.location = i + 1;temp = [value substringWithRange:range];int _intvalue2 = [temp intValue];int intvalue = _intvalue1 | _intvalue2;bytes[0] = intvalue;[vdata appendBytes:&bytes length:1];i += 2;}bytes[0] = 255;[vdata appendBytes:&bytes length:1];bytes[0] = 255;[vdata appendBytes:&bytes length:1];bytes[0] = 255;[vdata appendBytes:&bytes length:1];bytes[0] = 255;[vdata appendBytes:&bytes length:1];return [vdata autorelease];}