我正在尝试在我的基于视图的应用程序中部署以下代码,但是当我尝试运行它时出现以下错误:
GPSViewController.h
CLLocationManager *lm;
CLLocation *firstLocation;
CLLocation *secondLocation;
CLLocationDistance *distance;
NSString *distanceString;
GPSViewController.m
firstLocation = [[[CLLocation alloc] initWithLatitude:lat1 longitude:lon1] autorelease];
secondLocation = [[[CLLocation alloc] initWithLatitude:lat2 longitude:lon2] autorelease];
distance = [secondLocation distanceFromLocation:firstLocation]; //CLLocation may not respond to distanceFromLocation
double dist = distance / 1000; //invalid operands to binary
distanceString = [[NSString alloc] stringWithFormat: @"%f", dist];
NSLog(@"the distance between the two points is: %@", distanceString);
在上面的示例代码中,如何将变量“distance”从“CLLocationDistance”类型转换为“double”类型?
我只是想使用两个不同的 CLLocation 对象计算两点之间的距离,并将其打印到控制台。lat1, lon1, lat2, lon2 是双打。
谁能看到我哪里出错了?