如何根据坐标过滤数据?

时间:2013-02-27 00:35:58

标签: iphone ios objective-c mkmapview

在我的应用程序中,我有很多位置,并且根据当前位置,我需要过滤结果并仅显示5英里半径范围内的结果。 有没有办法实现这个?

谢谢,

3 个答案:

答案 0 :(得分:2)

CLLocation有distanceFromLocation,可以像

一样调用
CLLocation dist = [locationA distanceFromLocation:locationB];

答案 1 :(得分:1)

试试这个功能。这会对你有所帮助。

-(void)distanceBetween{


double latitude1 = [merchant.latitude doubleValue];
double longitude1 = [merchant.longitude doubleValue];

NSUserDefaults *userLocation = [NSUserDefaults standardUserDefaults];
float lat = [userLocation floatForKey:@"latitude"];
float lon = [userLocation floatForKey:@"longitude"];


CLLocation *locA = [[CLLocation alloc] initWithLatitude:latitude1 longitude:longitude1];
CLLocation *locB = [[CLLocation alloc] initWithLatitude:lat longitude:lon];

CLLocationDistance distanceTo = [locA distanceFromLocation:locB];
NSLog(@"locaA is %f", locA);
NSLog(@"locaB is %f", locB);
NSLog(@"locdistnace is %f", distanceTo);
[[self distance] setText:[NSString stringWithFormat:@"%0.2f miles", distanceTo/1609.34]];

}

答案 2 :(得分:1)

这样的事情应该有效,但是没有测试过:

- (NSArray *)filterArrayOfLocations:(NSArray *)array byDistance:(CLLocationDistance)distance toCurrentLocation:(CLLocation*)currentLocation
{
    NSArray *filteredArray = [array filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
        return [currentLocation distanceFromLocation:(CLLocation *)evaluatedObject] < distance;
    }]];
    return filteredArray;
}