在iOS应用程序服务器上的文本文件中搜索纬度和经度范围

我试图在一个文本文件（可在url上找到）中搜索，其中有纬度、经度和其他用逗号分隔的信息。 我需要在应用程序中搜索距离用户所选纬度最近的纬度。 代码是用来读取该文件并进行搜索的，但它不能完美地工作。 请让我知道，在这种情况下我应该如何处理。 1） 文件得到实时更新，所以每次用户选择位置并单击获取信息时，我都需要调用url并读取文件。 2） 然后搜索距离用户所选lat lon最近的lat lon

NSDICTIONARY数据获取：-

(
    {
    "altitude_m" = "90.0";
    engName = “Station 1”;
    grkName = "\U039d\U03ad\U03b1 \U039c\U03ac\U03ba\U03c1\U03b7 \U0391\U03c4\U03c4\U03b9\U03ba\U03ae\U03c2";
    "humidity_P" = "50.0";
    lat = "38.058873";
    "local_time" = "16:20";
    lon = "23.976741";
    "pressure_hPA" = "1019.9";
    "rain_mm" = "0.0";
    "tem_C" = "17.2";
    "wind_Gusts_khm" = "51.5";
    "wind_degrees" = "22.5";
    "wind_kmh" = "25.7";
}
{
    "altitude_m" = "90.0";
    engName = “Station 2”;
    grkName = "\U039d\U03ad\U03b1 \U039c\U03ac\U03ba\U03c1\U03b7 \U0391\U03c4\U03c4\U03b9\U03ba\U03ae\U03c2";
    "humidity_P" = "50.0";
    lat = "38.048873";
    "local_time" = "16:20";
    lon = "23.876741";
    "pressure_hPA" = "1019.9";
    "rain_mm" = "0.0";
    "tem_C" = "17.2";
    "wind_Gusts_khm" = "51.5";
    "wind_degrees" = "22.5";
    "wind_kmh" = "25.7";
}
{
    "altitude_m" = "90.0";
    engName = “Station 3”;
    grkName = "\U039d\U03ad\U03b1 \U039c\U03ac\U03ba\U03c1\U03b7 \U0391\U03c4\U03c4\U03b9\U03ba\U03ae\U03c2";
    "humidity_P" = "50.0";
    lat = "38.059873";
    "local_time" = "16:20";
    lon = "23.986741";
    "pressure_hPA" = "1019.9";
    "rain_mm" = "0.0";
    "tem_C" = "17.2";
    "wind_Gusts_khm" = "51.5";
    "wind_degrees" = "22.5";
    "wind_kmh" = "25.7";
}

//匹配功能：-

-(void)matchLAtLongNow: (NSString *)latitude :(NSString *)longitude {


CLLocationCoordinate2D pinlocation;

pinlocation.latitude   = [latitude doubleValue];

pinlocation.longitude  = [longitude doubleValue];


float minLat = pinlocation.latitude - (searchDistance / 69);

float maxLat = pinlocation.latitude + (searchDistance / 69);


float minLon = pinlocation.longitude - searchDistance / fabs(cos(deg2rad(pinlocation.latitude))*69);
float maxLon = pinlocation.longitude + searchDistance / fabs(cos(deg2rad(pinlocation.longitude))*69);

NSPredicate *predicate = [NSPredicate predicateWithFormat:
                          @"lat <= %f AND lat >= %f AND lon <= %f AND lon >= %f",
                          maxLat, minLat, maxLon, minLon];

MatchedTxtArray = [myArray filteredArrayUsingPredicate:applePred];


}

-（void）matchLAtLongNow:（NSString*）纬度：（NSString*）经度{
CLLOCATIONCoordinated2D引脚定位；
pinlocation.latitude=[latitude doubleValue]；
pinlocation.longitude=[longitude doubleValue]；
float minLat=pinlocation.latitude-（搜索距离/69）；
float maxLat=pinlocation.latitude+（搜索距离/69）；
float minLon=pinlocation.longitude-searchDistance/fabs（cos（deg2rad（pinlocation.latitude））*69）；
float maxLon=pinlocation.longitude+searchDistance/fabs（cos（deg2rad（pinlocation.longitude））*69）；
NSPredicate*谓词=[NSPredicate谓词格式：
@“lat=%f和lon=%f”，
maxLat，minLat，maxLon，minLon]；
MatchedTxtArray=[myArray filteredArrayUsingPredicate:applePred]；
}

//获取错误 *由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：'-[\uu NSCFNumber\u fastCStringContents]：未识别的选择器发送到实例0x175426460'

---

*第一次抛出调用堆栈：

NSDictionary返回NSNumber。检查调用matchAtLongNow的位置：您可能在需要字符串的位置有NSNumber

听起来您需要地理搜索，而不是包含在某些阈值内。我会重新表述如下：

NSArray *objects; // this is your parsed file, an array of dictionaries
CLLocation *userLocation;  // this is your user location

// sort the dictionary in order of distance to the userLocation
NSArray *sortedObjects = [objects sortedArrayUsingComparator:^(NSDictionary *objA,NSDictionary *objB) {
    CLLocationDistance distanceA = [self distanceToObject:objA from:userLocation];
    CLLocationDistance distanceB = [self distanceToObject:objB from:userLocation];
    return (NSComparisonResult)(distanceB-distanceA);
}];

sortedObjects

将包含从距离

用户位置最近到最远排序的字典

我们只需要一个函数，该函数生成字典中lat/lon值到用户位置的距离

- (CLLocationDistance)distanceToObject:(NSDictionary *)object from:(CLLocation *)location {
    CLLocationDegrees latitude = [object[@"lat"] doubleValue];
    CLLocationDegrees longitude = [object[@"lob"] doubleValue];
    CLLocation *objectLocation = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude];
    return [objectLocation distanceFromLocation:location];
}

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谢谢你的回复。我检查了一下是否有字符串。