ios - iOS找到平均速度

Question

我已经有一些东西可以显示我当前的速度和最高速度(下面的代码中的最大速度)，现在我想做一些计算核心位置平均速度的东西。怎么样？谢谢。

- (void)locationUpdate:(CLLocation *)location {
speedLabel.text = [NSString stringWithFormat:@"%.2f", [location speed]*2.236936284];

这是最高速度的浮标

   float currentSpeed = [location speed]*2.236936284;
if(currentSpeed - maxSpeed >= 0.01){
    maxSpeed = currentSpeed;
    maxspeedlabel.text = [NSString stringWithFormat: @"%.2f", maxSpeed];

}

Answer 1

声明变量是您的* .m类

@implementation your_class
{
    CLLocationDistance _distance;
    CLLocation *_lastLocation;
    NSDate *_startDate;
}

在您的 init或 viewDidLoad方法中，将它们设置为初始值

_distance = 0;
_lastLocation = nil;
_startDate = nil;

将 locationUpdate:更改为

- (void)locationUpdate:(CLLocation *)location {
    speedLabel.text = [NSString stringWithFormat:@"%.2f", [location speed]*2.236936284];
    if (_startDate == nil) // first update!
    {
        _startDate = location.timestamp;
        _distance = 0;
    }
    else
    {
        _distance += [location distanceFromLocation:_lastLocation];
        _lastLocation = location;
        NSTimeInterval travelTime = [location.timestamp timeIntervalSinceDate:_startDate];
        if (travelTime > 0)
        {
            double avgSpeed = _distance / travelTime;
            AVGspeedlabel.text = [NSString stringWithFormat: @"%.2f", avgSpeed];
            NSLog(@"Average speed %.2f", avgSpeed);
        }
    }
}

重置平均速度

_startDate = nil;
_distance = 0;