我是
Objective-c的新手,所以如果我的问题太垃圾,我想道歉.
我正在编程指南针然而,它正在工作(感谢教程).
给出实际位置(经度和纬度).
罗盘内的箭头是否可以显示指向特定位置(经度2和纬度2)的方向？
我已经读过,我必须考虑iphone的磁性和真实标题.
解决方法
- (void)locationManager:(CLLocationManager *)manager didUpdateHeading:(CLHeading *)newHeading {
double heading = newHeading.trueHeading; //in degree relative to true north
double bearing = ... //get current bearing in degree relative to true north
//with the JS library mentioned below it would be something like
//bearing = userLoc.bearingTo(destionation);
//just two lines,the the sake of the example
double rotationInDegree = (bearing - heading); //the important line
rotationInDegree = fmod((rotationInDegree + 360),360); //just to be on the safe side :-)
compassViewPerhapsAsImage.transform=CGAffineTransformMakeRotation(DegreesToRadians(rotationInDegree));
}
计算轴承的良好链接：
> http://www.movable-type.co.uk/scripts/latlong.html有eplanations和Javascript exampless,但很容易转换！