目标C / iOS -从设备运动间距值更新数组

Question

新站点和Obj C.试图从设备运动(工作)中获得音调值，放入具有最近60个值(不工作)的数组中，并选择数组内的最大值。对于来自设备的每个新音高值，新的音高值被添加到数组中，第61个值被删除。当我连接我的手机并运行时，我得到pitch和maxPitch的log值;然而，我没有得到60个值的数组，所以我不相信它是正常工作的。非常感谢任何帮助。

我认为问题可能出在这一行。Count <= 60) {

[pitchArray addObject:[NSString stringWithFormat:@"%。2º"，motion.attitude.pitch * kRadToDeg];

下面是完整的代码:

#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

每次获得新的音高值时，都要分配一个新的数组。所以你应该将pitch数组定义为一个属性并在你的动作更新处理器之前分配它。你的代码应该是:

@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，所以我把if/else语句改为while。代码现在可以工作并输出60项数组和最大值。