SkiaRasterLayer¶
Namespace: ThinkGeo.Core
Draws standard bitmap formats (BMP, JPG, PNG, etc.) that are supported by Skia and geo-referenced via a world file.
public class SkiaRasterLayer : RasterLayer
Inheritance Object → LayerBase → Layer → RasterLayer → SkiaRasterLayer
Remarks:
Each image must have a corresponding world file that supplies the geographic extent so the raster can be positioned on the map.
Properties¶
HasBoundingBox¶
Gets a value indicating that the layer can provide a bounding box derived from the world file or supplied extent.
public bool HasBoundingBox { get; }
Property Value¶
ImagePathFilename¶
Gets or sets the image path used by the layer.
public string ImagePathFilename { get; set; }
Property Value¶
ResamplingMode¶
Gets or sets the Skia sampling mode used by this layer's image source. Default is RasterResamplingMode.Auto.
public RasterResamplingMode ResamplingMode { get; set; }
Property Value¶
ImageSource¶
This property gets and sets the Image used by the RasterLayer.
public RasterSource ImageSource { get; protected set; }
Property Value¶
RasterSource
This property gets the Image used by the RasterLayer.
Remarks:
The set for this property is protected and only intended to be used by developers who are creating their own ImageSources. This is the main property to set for developers who are creating their own RasterLayer derivatives.
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 double.min. 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 double.min. This means the image should always display.
ScaleFactor¶
The scale factor when drawing the primitive image. For example I am looking for an image with 100100px, If the ScaleFactor is set to 2, it means the component will get the image with 200200px. We want to keep it as 1 (by default) for most cases.
public double ScaleFactor { get; set; }
Property Value¶
Projection¶
Gets the projection used by the underlying RasterLayer.ImageSource.
public Projection Projection { get; }
Property Value¶
RequestDrawingInterval¶
Gets or sets the interval between automatic draw requests. Obsolete.
public TimeSpan RequestDrawingInterval { get; set; }
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¶
Boolean
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¶
Boolean
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.
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¶
Single
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¶
Single
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¶
Single
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¶
Single
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¶
Boolean
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¶
Boolean
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¶
SkiaRasterLayer()¶
Initializes a new instance of the SkiaRasterLayer class with no associated file.
public SkiaRasterLayer()
SkiaRasterLayer(String)¶
Initializes a new instance of the SkiaRasterLayer class using the specified image file.
public SkiaRasterLayer(string imagePathFilename)
Parameters¶
imagePathFilename String
The image path. For TIFF imagery, prefer for better performance.
SkiaRasterLayer(String, String)¶
Initializes a new instance of the SkiaRasterLayer class using explicit image and world files.
public SkiaRasterLayer(string imagePathFilename, string worldFilePathFilename)
Parameters¶
imagePathFilename String
The image path. For TIFF imagery, prefer .
worldFilePathFilename String
The matching world file path.
SkiaRasterLayer(String, RectangleShape)¶
Initializes a new instance of the SkiaRasterLayer class using an explicit geographic extent.
public SkiaRasterLayer(string imagePathFilename, RectangleShape imageExtent)
Parameters¶
imagePathFilename String
The image path. For TIFF imagery, prefer .
imageExtent RectangleShape
The geographic extent covered by the image.
Events¶
StreamLoading¶
Occurs when the layer needs a stream to load the raster, allowing callers to supply custom sources.
public event EventHandler<StreamLoadingEventArgs> StreamLoading;
DrawingProgressChanged¶
Occurs as the layer reports drawing progress (useful for async or tiled rendering scenarios).
public event EventHandler<DrawingProgressChangedEventArgs> DrawingProgressChanged;
RequestedDrawing¶
Raised after the drawing buffer elapses so consumers can handle a legacy drawing cycle. Obsolete.
public event EventHandler<RequestedDrawingLayerEventArgs> RequestedDrawing;
RequestingDrawing¶
Raised before the drawing buffer elapses so consumers can cancel a legacy drawing operation. Obsolete.
public event EventHandler<RequestingDrawingLayerEventArgs> RequestingDrawing;
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;