AGSSpatialReference Class Reference
Description
Instances of this class represent a spatial reference. Each spatial reference can be represented by either a well-known ID (wkid), or a well-known text (wkt). Spatial References define the spatial properties of a geometry, for instance the coordinate system it uses. There are 2 broad classes of coordinate systems - Geographic & Projected. A Geographic Coordinate system uses a 3-dimensional spherical surface to define locations on the earth. A Projected Coordinate system on the other hand uses a flat, 2-dimensional surface. More information about spatial references and coordinate systems is available here.
It is very important to associate spatial data, such as geometry objects, with corresponding spatial references.
- Defined in:
- AGSGeometry.h ( ArcGIS library)
- Since:
- 1.0
Public Member Functions | |
| (double) | - convertValue:fromUnit: |
| (double) | - convertValue:toUnit: |
| (void) | - decodeWithJSON: |
| (NSDictionary *) | - encodeToJSON |
| (void) | - encodeToJSON:forKey: |
| (id) | - initWithJSON: |
| (id) | - initWithWKID: |
| (id) | - initWithWKID:WKT: |
| (id) | - initWithWKT: |
| (BOOL) | - isAnyWebMercator |
| (BOOL) | - isEqualToSpatialReference: |
| (BOOL) | - isWGS84 |
| (AGSSRUnit) | - unit |
Static Public Member Functions | |
| (id) | + spatialReferenceWithWKID: |
| (id) | + spatialReferenceWithWKID:WKT: |
| (id) | + spatialReferenceWithWKT: |
| (AGSSpatialReference *) | + webMercatorSpatialReference |
| (AGSSpatialReference *) | + wgs84SpatialReference |
Properties | |
| NSUInteger | wkid |
| NSString * | wkt |
Member Function Documentation
| - (double) convertValue: | (double) | val | ||
| fromUnit: | (AGSSRUnit) | fromUnit | ||
Converts the value from a specified unit to the same unit as the current spatial reference. Will return nan if trying to convert between angular and linear units, for example, Decimal Degrees and Meters.
- Parameters:
-
val The value to convert. fromUnit The unit to convert from.
- Returns:
- The converted value.
- Since:
- 1.8
| - (double) convertValue: | (double) | val | ||
| toUnit: | (AGSSRUnit) | unit | ||
Converts the value in the same unit as the current spatial reference to a specified unit. Will return nan if trying to convert between angular and linear units, for example, Decimal Degrees and Meters.
- Parameters:
-
val The value to convert. unit The unit to convert to.
- Returns:
- The converted value.
- Since:
- 1.8
| - (void) decodeWithJSON: | (NSDictionary *) | json | [optional, inherited] |
Decode object from JSON representation.
- Parameters:
-
json The JSON representation of the object to be decoded.
- Since:
- 1.0
| - (NSDictionary *) encodeToJSON | [optional, inherited] |
Encode and return JSON representation for object.
- Returns:
- JSON representation of object.
- Since:
- 1.0
| - (void) encodeToJSON: | (NSMutableDictionary*) | json | ||
| forKey: | (NSString*) | key | ||
Encodes spatial reference to json conditionally based on existence of a wkt
- Parameters:
-
json The dictionary to encode spatial reference to. key The encoded spatial reference is paired with.
- Since:
- 1.0
| - (id) initWithJSON: | (NSDictionary *) | json | [optional, inherited] |
Initialize and return object from JSON representation.
- Parameters:
-
json The JSON representation of the object to be created.
- Returns:
- Object decoded from JSON representation.
- Since:
- 1.0
| - (id) initWithWKID: | (NSUInteger) | wkid |
Initialize a spatial reference with wkid.
- Parameters:
-
wkid The well-known ID to initialize the spatial reference with.
- Since:
- 1.0
| - (id) initWithWKID: | (NSUInteger) | wkid | ||
| WKT: | (NSString *) | wkt | ||
Initialize spatial reference with well-known ID and text. This is the designated initializer.
- Parameters:
-
wkid The well-known ID. wkt The well-known text.
- Returns:
- A new spatial reference object.
- Since:
- 1.0
| - (id) initWithWKT: | (NSString *) | wkt |
Initialize a spatial reference with wkt.
- Parameters:
-
wkt The well-known text to initialize the spatial reference with.
- Since:
- 1.0
| - (BOOL) isAnyWebMercator |
Returns YES if wkid equals any of the "web mercator" projections.
- Since:
- 1.0
| - (BOOL) isEqualToSpatialReference: | (AGSSpatialReference *) | sr |
Returns YES if spatial references are both web mercator. If not, it will return YES if wkid or wkt are equal.
- Since:
- 1.0
| - (BOOL) isWGS84 |
Returns YES if wkid equals 4326.
- Since:
- 1.0
| + (id) spatialReferenceWithWKID: | (NSUInteger) | wkid |
Initialize an autoreleased spatial reference with wkid.
- Parameters:
-
wkid The well-known ID to initialize the spatial reference with.
- Since:
- 1.0
| + (id) spatialReferenceWithWKID: | (NSUInteger) | wkid | ||
| WKT: | (NSString *) | wkt | ||
Create new autoreleased spatial reference object.
- Parameters:
-
wkid The well-known ID. wkt The well-known text.
- Returns:
- A new spatial reference object.
- Since:
- 1.0
| + (id) spatialReferenceWithWKT: | (NSString *) | wkt |
Initialize an autoreleased spatial reference with wkt.
- Parameters:
-
wkt The well-known text to initialize the spatial reference with.
- Since:
- 1.0
| - (AGSSRUnit) unit |
The units that the spatial reference coordinates are in.
- Since:
- 1.8
| + (AGSSpatialReference *) webMercatorSpatialReference |
Returns a spatial reference object in web mercator.
- Since:
- 1.8
| + (AGSSpatialReference *) wgs84SpatialReference |
Returns a spatial reference object in WGS84 (4326).
- Since:
- 1.8
Property Documentation
- (NSUInteger) wkid [read, assign] |
The well-known ID of the spatial reference.
- Since:
- 1.0
- (NSString*) wkt [read, copy] |
The well-known text of the spatial reference.
- Availability:
- This feature is only available with services from ArcGIS Server 10.0 or above
- Since:
- 1.0