iphone - getDistanceFrom Vs distanceFromLocation

我在使用getDistanceFrom和distanceFromLocation时遇到问题。 getDistanceFrom已过时，iOS 4.1已弃用，而distanceFromLocation在3.1.3中不可用，如何解决此问题。

还有其他人遇到这个问题吗？

目前，我的代码是：

CLLocationDistance kilometers;
        if ([currentLocation respondsToSelector: @selector(distanceFromLocation:)])
        {
            kilometers = [currentLocation distanceFromLocation:previousLocation] / 1000;
        }
        else
        {
            //kilometers = [currentLocation getDistanceFrom:previousLocation] / 1000;
            kilometers = [currentLocation performSelector: @selector(getDistanceFrom:) withObject: previousLocation] / 1000;
        }

根据我使用的是哪个iOS，我会在行上获取“无效的操作数二进制”：

kilometers = [currentLocation distanceFromLocation:previousLocation] / 1000;
            kilometers = [currentLocation performSelector: @selector(getDistanceFrom:) withObject: previousLocation] / 1000;

问候，
史提芬

最佳答案

CédricLuthi的blog post对此有一个很好的解决方案。

简而言之，您需要在main.m中输入以下内容并确保#import <objc/runtime.h>：

Method getDistanceFrom = class_getInstanceMethod([CLLocation class], @selector(getDistanceFrom:));
class_addMethod([CLLocation class], @selector(distanceFromLocation:), method_getImplementation(getDistanceFrom), method_getTypeEncoding(getDistanceFrom));

然后，您可以在任何操作系统上使用distanceFromLocation:。