iOS -- 字符串(NSString *)转uint8_t的两种方法

// 第一种
NSString *connID = ((Collector *)weakSelf.globalMutableArray[i]).orignalConnID;
                    const uint8_t a = [[connID substringToIndex:2] intValue];
                    NSRange bRange = {2, 2};
                    const uint8_t b = [[connID substringWithRange:bRange] intValue];
                    NSRange cRange = {4, 2};
                    const uint8_t c = [[connID substringWithRange:cRange] intValue];
                    const uint8_t d = [[connID substringFromIndex:6] intValue];

   //第二种
                    NSString *str = @"AA21f0c1762a3abc299c013abe7dbcc50001DD";
                    NSData* bytes = [str dataUsingEncoding:NSUTF8StringEncoding];
                    Byte * myByte = (Byte *)[bytes bytes];
                    NSLog(@"myByte = %hhu",myByte[0]);
                    NSMutableData* data = [NSMutableData data];
                    NSScanner* scanner = [NSScanner scannerWithString:@"AA"];
                    unsigned intValue;
                    [scanner scanHexInt:&intValue];
                    [data appendBytes:&intValue length:1];
                    Byte * yte = (Byte *)[data bytes];
                    // 拿到的数据
                    const uint8_t senddata[] = {0xEB, 0x90, 0x00, 0x05, 0x06, a, b, c, d, 0x87};

觉得有用还是没用都评论哦! ^..^!!!