AzureMapsRasterAsyncLayer¶
Namespace: ThinkGeo.Core
Represents a layer for displaying raster tiles from the Azure Maps server.
public class AzureMapsRasterAsyncLayer : WebRasterXyzTileAsyncLayer, IHttpRequestService
Inheritance object → LayerBase → AsyncLayer → XyzTilesAsyncLayer → RasterXyzTileAsyncLayer → WebRasterXyzTileAsyncLayer → AzureMapsRasterAsyncLayer
Implements IHttpRequestService
Remarks:
Attribution corresponding to the current scale and extent (retrieved via GetAttributionAsync()) must be displayed on top of the map, as required by Azure Maps licensing terms. Refer to the official Azure Maps documentation to ensure compliance, or use AzureMapsRasterOverlay to handle license and attribution requirements automatically.
Properties¶
SubscriptionKey¶
Gets or sets the Azure Maps subscription key used to authenticate tile requests.
public string SubscriptionKey { get; set; }
Property Value¶
ApiVersion¶
Gets or sets the Azure Maps REST API version used when requesting tiles.
public string ApiVersion { get; set; }
Property Value¶
RasterTileSet¶
Gets or sets the Azure Maps raster tile set that defines the requested imagery.
public AzureMapsRasterTileSet RasterTileSet { get; set; }
Property Value¶
HttpClient¶
Gets or sets the HTTP client used to download tiles.
public HttpClient HttpClient { get; set; }
Property Value¶
WebProxy¶
Gets or sets the proxy applied to HTTP requests.
public IWebProxy WebProxy { get; set; }
Property Value¶
TimeoutInSeconds¶
Gets or sets the request timeout, in seconds.
public int TimeoutInSeconds { get; set; }
Property Value¶
Credentials¶
Gets or sets the credential provider used for HTTP authentication.
public ICredentials Credentials { get; set; }
Property Value¶
UserAgent¶
This property allows you to specify a custom user-agent request header when making requests to a Web server. This header provides information about the client application or device and can be useful for server-side logging and analytics.
public string UserAgent { get; set; }
Property Value¶
HttpMessageHandler¶
Gets or sets the HTTP message handler used when constructing WebRasterXyzTileAsyncLayer.HttpClient.
public HttpMessageHandler HttpMessageHandler { get; set; }
Property Value¶
MaxZoomOfTheData¶
Gets or sets the highest zoom level available from the server or cache.
public int MaxZoomOfTheData { get; set; }
Property Value¶
MinZoomOfTheData¶
Gets or sets the lowest zoom level available from the server or cache.
public int MinZoomOfTheData { get; set; }
Property Value¶
RenderBeyondMinZoom¶
Gets or sets a value indicating whether tiles should be down-sampled beyond RasterXyzTileAsyncLayer.MinZoomOfTheData.
public bool RenderBeyondMinZoom { get; set; }
Property Value¶
UpperThreshold¶
This property gets and sets the upper threshold in the scale at which to display the image.
public double UpperThreshold { get; set; }
Property Value¶
double
This property gets the upper threshold in the scale at which to display the image.
Remarks:
Above the upper threshold in scale, the image will not be displayed. This, in conjunction with the LowerThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
LowerThreshold¶
This property gets and sets the lower threshold in the scale at which to display the image.
public double LowerThreshold { get; set; }
Property Value¶
double
This property gets the lower threshold in the scale at which to display the image.
Remarks:
Below the lower threshold in scale, the image will not be displayed. This, in conjunction with the UpperThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
UpperScale¶
This property gets and sets the upper threshold in the scale at which to display the image.
public double UpperScale { get; set; }
Property Value¶
double
This property gets the upper threshold in the scale at which to display the image.
Remarks:
Above the upper threshold in scale, the image will not be displayed. This, in conjunction with the LowerThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
LowerScale¶
This property gets and sets the lower threshold in the scale at which to display the image.
public double LowerScale { get; set; }
Property Value¶
double
This property gets the lower threshold in the scale at which to display the image.
Remarks:
Below the lower threshold in scale, the image will not be displayed. This, in conjunction with the UpperThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
RenderBeyondMaxZoom¶
Gets or sets a value indicating whether tiles should be up-sampled beyond RasterXyzTileAsyncLayer.MaxZoomOfTheData.
public bool RenderBeyondMaxZoom { get; set; }
Property Value¶
TileCache¶
Gets or sets the primary raster tile cache used for storing downloaded tiles.
public RasterTileCache TileCache { get; set; }
Property Value¶
ProjectedTileCache¶
Gets or sets the cache that stores reprojected tiles when a projection converter is in use.
public RasterTileCache ProjectedTileCache { get; set; }
Property Value¶
IsCacheOnly¶
Gets or sets a value indicating whether the layer should read exclusively from cache.
public bool IsCacheOnly { get; set; }
Property Value¶
ProjectionConverter¶
Gets or sets the projection converter used to transform coordinates during rendering.
public ProjectionConverter ProjectionConverter { get; set; }
Property Value¶
TileMatrixSet¶
Gets or sets the tile matrix set describing the XYZ grid.
public TileMatrixSet TileMatrixSet { get; set; }
Property Value¶
TileWidth¶
Gets or sets the TileWidth.
public int TileWidth { get; set; }
Property Value¶
TileHeight¶
Gets or sets the TileHeight.
public int TileHeight { get; set; }
Property Value¶
MaxExtent¶
This is the full extent of the matrix griding the xyz tiles. It's NOT the bounding box of the data itself.
public RectangleShape MaxExtent { get; set; }
Property Value¶
MapUnit¶
Gets or sets the MapUnit.
public GeographyUnit MapUnit { get; set; }
Property Value¶
HasBoundingBox¶
Gets or sets the HasBoundingBox.
public bool HasBoundingBox { get; }
Property Value¶
Name¶
Gets or sets the display name for the layer.
public string Name { get; set; }
Property Value¶
string
The name used to identify the layer within UI components such as legends.
Remarks:
The name is user defined. Assign a descriptive value so tooling such as legends and layer lists can surface a meaningful label to end users.
IsOpen¶
Gets a value indicating whether the layer is currently open.
public bool IsOpen { get; }
Property Value¶
bool
true if the layer has completed its open routine; otherwise, false.
Remarks:
This method is the concrete wrapper for the abstract method IsOpenCore. Various methods on the Layer require that it be in an open state. If one of those methods is called when the state is not open, then the method will throw an exception. To enter the open state, you must call the Layer Open method. The method will raise an exception if the current Layer is already open.
As this is a concrete public method that wraps a Core method, we reserve the right to add events and other logic to pre- or post-process data returned by the Core version of the method. In this way, we leave our framework open on our end, but also allow you the developer to extend our logic to suit your needs. If you have questions about this, please contact our support team as we would be happy to work with you on extending our framework.
IsVisible¶
Gets or sets a value indicating whether the layer is visible.
public bool IsVisible { get; set; }
Property Value¶
bool
true to draw the layer; otherwise, false.
Remarks:
If this property is set to false, the layer will not draw. We ensure this in the Draw method. This is useful for legends and other controls that control the visibility of layers.
DrawingTime¶
Gets the last recorded drawing time for the layer.
public TimeSpan DrawingTime { get; protected set; }
Property Value¶
TimeSpan
The duration of the most recent draw operation.
Remarks:
We track the drawing time for the layer and report it back in this method. This is useful for determining the speed of various layers.
Projection¶
Gets the projection of the layer.
public Projection Projection { get; set; }
Property Value¶
DrawingExceptionMode¶
Gets or sets how drawing exceptions are handled when the layer renders.
public DrawingExceptionMode DrawingExceptionMode { get; set; }
Property Value¶
Background¶
Gets or sets the background color used when rendering the layer.
public GeoColor Background { get; set; }
Property Value¶
GeoColor
The fill applied to areas not covered by layer content.
Transparency¶
Gets or sets the amount of transparency applied to the rendered image.
public float Transparency { get; set; }
Property Value¶
float
A value between 0 (fully transparent) and 255 (fully opaque).
BlueTranslation¶
Gets or sets the intensity adjustment applied to the blue channel.
public float BlueTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the blue channel translation.
RedTranslation¶
Gets or sets the intensity adjustment applied to the red channel.
public float RedTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the red channel translation.
GreenTranslation¶
Gets or sets the intensity adjustment applied to the green channel.
public float GreenTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the green channel translation.
KeyColors¶
Gets the collection of key colors that should be rendered as transparent.
public Collection<GeoColor> KeyColors { get; }
Property Value¶
Remarks:
Attempting to access this collection when the associated GeoCanvas does not support key colors (see GeoCanvas.SupportKeyColor) results in an exception. Add colors to this collection to ensure they render as transparent.
IsNegative¶
Gets or sets a value indicating whether the image should be rendered with inverted colors.
public bool IsNegative { get; set; }
Property Value¶
bool
true to invert the color channels; otherwise, false.
IsGrayscale¶
Gets or sets a value indicating whether the image should be converted to grayscale prior to rendering.
public bool IsGrayscale { get; set; }
Property Value¶
bool
true to apply a grayscale filter; otherwise, false.
ThreadSafe¶
Gets or sets the threading guarantees provided by the layer implementation.
public ThreadSafetyLevel ThreadSafe { get; set; }
Property Value¶
ThreadSafetyLevel
The level of thread safety that callers can expect when interacting with the layer.
ColorMappings¶
Gets the color translation map that will be applied when rendering the layer.
public Dictionary<GeoColor, GeoColor> ColorMappings { get; }
Property Value¶
Dictionary<GeoColor, GeoColor>
WrappingMode¶
Gets or sets how the layer wraps when the map extent crosses world boundaries.
public WrappingMode WrappingMode { get; set; }
Property Value¶
WrappingExtent¶
Gets or sets the geographic extent to use when wrapping is enabled.
public RectangleShape WrappingExtent { get; set; }
Property Value¶
Constructors¶
AzureMapsRasterAsyncLayer()¶
Initializes a new instance of the AzureMapsRasterAsyncLayer class with the default tile set.
public AzureMapsRasterAsyncLayer()
AzureMapsRasterAsyncLayer(string, AzureMapsRasterTileSet)¶
Initializes a new instance of the AzureMapsRasterAsyncLayer class.
public AzureMapsRasterAsyncLayer(string subscriptionKey, AzureMapsRasterTileSet rasterTileSet)
Parameters¶
subscriptionKey string
The Azure Maps subscription key used to authorize requests.
rasterTileSet AzureMapsRasterTileSet
The Azure Maps raster tile set to request.
Methods¶
GetRasterContentTypeCore()¶
Returns a content hint based on the selected Azure Maps tile set.
protected RasterContentType GetRasterContentTypeCore()
Returns¶
GetTileSetId(AzureMapsRasterTileSet)¶
Gets the Azure Maps tileset identifier for the specified AzureMapsRasterTileSet.
public static string GetTileSetId(AzureMapsRasterTileSet tileSet)
Parameters¶
tileSet AzureMapsRasterTileSet
The configured raster tile set.
Returns¶
string
The Azure Maps identifier that corresponds to the supplied tile set.
Exceptions¶
ArgumentOutOfRangeException
Thrown when the tile set is not recognized.
GetAttributionAsync(RectangleShape, double)¶
Gets the attribution text required for the specified extent and scale.
public Task<string> GetAttributionAsync(RectangleShape extentInDecimalDegree, double scale)
Parameters¶
extentInDecimalDegree RectangleShape
The geographic extent expressed in decimal degrees.
scale double
The scale used to determine the zoom level.
Returns¶
Task<string>
A task that returns the attribution string, or an empty string when none is available.
OpenAsyncCore(CancellationToken)¶
Opens the layer and attaches the Azure Maps subscription key header.
protected Task OpenAsyncCore(CancellationToken cancellationToken)
Parameters¶
cancellationToken CancellationToken
The cancellation token used to abort the asynchronous operation.
Returns¶
GetImageUriAsyncCore(int, long, long, float)¶
Builds the Azure Maps tile URI for the supplied XYZ indices.
protected Task<string> GetImageUriAsyncCore(int zoomLevel, long x, long y, float resolutionFactor)
Parameters¶
zoomLevel int
The zoom level requested.
x long
The tile column.
y long
The tile row.
resolutionFactor float
The resolution factor applied to the request.
Returns¶
Task<string>
A task that returns the request URI for the specified tile.
Events¶
SendingHttpRequest¶
Occurs before an HTTP request is sent so subclasses can inspect or cancel it.
public event EventHandler<SendingHttpRequestMessageEventArgs> SendingHttpRequest;
ReceivedHttpResponse¶
Occurs after an HTTP response is received.
public event EventHandler<ReceivedHttpResponseMessageEventArgs> ReceivedHttpResponse;
TileCacheGenerated¶
Occurs each time a tile is generated during the execution of RasterXyzTileAsyncLayer.GenerateTileCacheAsync(RectangleShape, int, int, float, OverwriteMode, CancellationToken).
public event EventHandler<TileCacheGeneratedXyzTileAsyncLayerEventArgs> TileCacheGenerated;
DrawingException¶
Occurs when the DrawingException event is raised.
public event EventHandler<DrawingExceptionLayerEventArgs> DrawingException;
DrawnException¶
Occurs when the DrawnException event is raised.
public event EventHandler<DrawnExceptionLayerEventArgs> DrawnException;