有人能告诉我如何在苹果 map 中绘制 GeoJson 文件作为叠加层吗?我想要一个完整的示例,我的形状是多边形还是多边形?
此文件 Countries GeoJSON如果您向我提供代码或库以使用 MKMapView
最佳答案
我找到了解决方案,以防有人也需要帮助。
@interface HHLViewController
+ (NSArray *)countriesOverlays;
@end
@implementation HHLViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *overlays = [HHLViewController countriesOverlays];
[self.stateMapView addOverlays:overlays];
}
+ (NSArray *)countriesOverlays {
NSString *fileName = [[NSBundle mainBundle] pathForResource:@"countries" ofType:@"json"];
NSData *overlayData = [NSData dataWithContentsOfFile:fileName];
NSArray *countries = [[NSJSONSerialization JSONObjectWithData:overlayData options:NSJSONReadingAllowFragments error:nil] objectForKey:@"features"];
NSMutableArray *overlays = [NSMutableArray array];
for (NSDictionary *country in countries) {
NSDictionary *geometry = country[@"geometry"];
if ([geometry[@"type"] isEqualToString:@"Polygon"]) {
MKPolygon *polygon = [HHLViewController overlaysFromPolygons:geometry[@"coordinates"] id:country[@"properties"][@"name"]];
if (polygon) {
[overlays addObject:polygon];
}
} else if ([geometry[@"type"] isEqualToString:@"MultiPolygon"]){
for (NSArray *polygonData in geometry[@"coordinates"]) {
MKPolygon *polygon = [HHLViewController overlaysFromPolygons:polygonData id:country[@"properties"][@"name"]];
if (polygon) {
[overlays addObject:polygon];
}
}
} else {
NSLog(@"Unsupported type: %@", geometry[@"type"]);
}
}
return overlays;
}
+ (MKPolygon *)overlaysFromPolygons:(NSArray *)polygons id:(NSString *)title
{
NSMutableArray *interiorPolygons = [NSMutableArray arrayWithCapacity:[polygons count] - 1];
for (int i = 1; i < [polygons count]; i++) {
[interiorPolygons addObject:[HHLViewController polygonFromPoints:polygons[i] interiorPolygons:nil]];
}
MKPolygon *overlayPolygon = [HHLViewController polygonFromPoints:polygons[0] interiorPolygons:interiorPolygons];
overlayPolygon.title = title;
return overlayPolygon;
}
+ (MKPolygon *)polygonFromPoints:(NSArray *)points interiorPolygons:(NSArray *)polygons
{
NSInteger numberOfCoordinates = [points count];
CLLocationCoordinate2D *polygonPoints = malloc(numberOfCoordinates * sizeof(CLLocationCoordinate2D));
NSInteger index = 0;
for (NSArray *pointArray in points) {
polygonPoints[index] = CLLocationCoordinate2DMake([pointArray[1] floatValue], [pointArray[0] floatValue]);
index++;
}
MKPolygon *polygon;
if (polygons) {
polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates interiorPolygons:polygons];
} else {
polygon = [MKPolygon polygonWithCoordinates:polygonPoints count:numberOfCoordinates];
}
free(polygonPoints);
return polygon;
}
@end
关于ios - 在 Apple Maps 中绘制 GeoJson 作为叠加层,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22823772/