Question

网站的新用户和Obj C.尝试从Device Motion（工作）获取音高值，放入具有最新60个值（不工作）的数组中，并选择数组中的最大值。对于来自设备的每个新音高值，新的音高值被添加到阵列中并且第61个值被丢弃。当我连接手机并运行时，我得到了音高和maxPitch的日志值;但是，我没有得到60个值的数组，所以我不相信它正常工作。任何帮助是极大的赞赏。

我认为问题可能在于：if（pitchArray.count＆lt; = 60）{

[pitchArray addObject：[NSString stringWithFormat：@“％。2gº”，motion.attitude.pitch * kRadToDeg]];

以下是完整代码：

#import "ViewController.h"
#import <CoreMotion/CoreMotion.h>

#define kRadToDeg   57.2957795

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *pitchLabel;
@property (nonatomic, strong) CMMotionManager *motionManager;

@end

@implementation ViewController

- (CMMotionManager *)motionManager
{
    if (!_motionManager) {
        _motionManager = [CMMotionManager new];
        [_motionManager setDeviceMotionUpdateInterval:1/60];
    }
    return _motionManager;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self.motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue] withHandler:^(CMDeviceMotion *motion, NSError *error) {

        self.pitchLabel.text = [NSString stringWithFormat:@"%.2gº", motion.attitude.pitch * kRadToDeg];

     NSMutableArray *pitchArray = [NSMutableArray array];
     pitchArray = [[NSMutableArray  alloc] initWithCapacity:60];

        if (pitchArray.count <= 60) {

            [pitchArray addObject:[NSString stringWithFormat:@"%.2gº", motion.attitude.pitch * kRadToDeg]];
        }
        else {

        [pitchArray removeObjectAtIndex:0];

        }

        NSNumber *maxPitch = [pitchArray valueForKeyPath:@"@max.intValue"];

        NSLog(@"%@",pitchArray);

        NSLog(@"Max Pitch Value = %d",[maxPitch intValue]);


      }];
}

 @end

Answer 1

每次获得新音高值时，您都会继续分配新数组。因此，您应将音高数组定义为属性，并在运动更新处理程序之前分配它。你的代码是：

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *pitchLabel;
@property (nonatomic, strong) CMMotionManager *motionManager;
@property (nonatomic, strong) NSMutableArray *pitchArray;

@end

@implementation ViewController

- (CMMotionManager *)motionManager
{
    if (!_motionManager) {
        _motionManager = [CMMotionManager new];
        [_motionManager setDeviceMotionUpdateInterval:1/60];
    }
    return _motionManager;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.pitchArray = [[NSMutableArray  alloc] initWithCapacity:60];

    [self.motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue] withHandler:^(CMDeviceMotion *motion, NSError *error) {

        self.pitchLabel.text = [NSString stringWithFormat:@"%.2gº", motion.attitude.pitch * kRadToDeg];

        if (self.pitchArray.count <= 60) {

            [self.pitchArray addObject:[NSString stringWithFormat:@"%.2gº", motion.attitude.pitch * kRadToDeg]];
        }
        else {

        [self.pitchArray removeObjectAtIndex:0];

        }

        NSNumber *maxPitch = [self.pitchArray valueForKeyPath:@"@max.intValue"];

        NSLog(@"%@",self.pitchArray);

        NSLog(@"Max Pitch Value = %d",[maxPitch intValue]);


      }];
}

Answer 2

啊，简单的错误。它没有循环，所以我将if / else语句更改为while。代码现在可以工作并输出60项数组和最大值。

Objective C / iOS - 从设备运动间距值更新数组

2 个答案: