InMemoryFeatureLayer¶
Namespace: ThinkGeo.Core
This layer is backed by memory and is typically used for temporary features.
public class InMemoryFeatureLayer : FeatureLayer
Inheritance Object → LayerBase → Layer → FeatureLayer → InMemoryFeatureLayer
Remarks:
This layer is backed by memory and is typically used for temporary features. You can use the MapShapes layer for user-drawn InternalFeatures, InternalFeatures that come from an external device such as a GPS unit, or any InternalFeatures that are not saved to disk or a database.
Properties¶
Columns¶
This property gets the columns of data for the InternalFeatures in this Layer.
public Collection<FeatureSourceColumn> Columns { get; }
Property Value¶
Collection<FeatureSourceColumn>
Remarks:
You should set the column names for the data that the InternalFeatures will hold. For example, if you have some features that represent road signs, then one column you may want to add is "Sign Type". Then, for every Feature you add to the layer, you need to add the "Sign Type" and a value to the InternalFeatures' ColumnValues dictionary. If you provide this information, then you can use things like ValueStyles, Labeling, etc. based on the columns you have defined.
InternalFeatures¶
This property gets the dictionary that holds your InternalFeatures.
public GeoCollection<Feature> InternalFeatures { get; }
Property Value¶
Remarks:
The dictionary is a quick way to access your InternalFeatures. You can easily add, remove or edit features in this dictionary and they instantly take effect in the layer. You can always use the EditTools to do the same thing, but this is a shortcut, as the data is backed in memory so it is very pliable.
HasBoundingBox¶
This property checks to see if a Layer has a BoundingBox or not. If it has no BoundingBox, it will throw an exception when you call the GetBoundingBox() and GetFullExtent() APIs. In InMemoryFeatureLayer, we override this API and mark it as true.
public bool HasBoundingBox { get; }
Property Value¶
Remarks:
The default implementation in the base class returns false.
Projection¶
public Projection Projection { get; }
Property Value¶
EditTools¶
This property gets the EditTools that allow you to easily edit InternalFeatures in the Feature Layer.
public EditTools EditTools { get; protected set; }
Property Value¶
This property gets the EditTools that allow you to easily edit InternalFeatures in the
Feature Layer.
Remarks:
The EditTools are supplied as an easily accessible wrapper for the editing methods of the FeatureSource.
FeatureIdsToExclude¶
A collection of strings representing record id of features not to get in the Layer.
public Collection<string> FeatureIdsToExclude { get; }
Property Value¶
Remarks:
This string collection is a handy place to specify what records not to get from the source. Suppose you have a shape file of roads and you want to hide the roads within a particular rectangle, simply execute GetFeaturesInsideBoundingBox() and add the id of the return features to the collection and forget about them. Since you can set this by Layer it makes is easy to determine what to and what not to.
QueryTools¶
This property gets the QueryTools that allow you to easily query Features from the Feature Layer.
public QueryTools QueryTools { get; protected set; }
Property Value¶
This property gets the QueryTools that allow you to easily query Features from the
Feature Layer.
Remarks:
This property gets the QueryTools that allow you to easily query Features from the Feature Layer. The QueryTools are supplied as an easily accessible wrapper for the query methods of the FeatureSource.
MaxRecordsToDraw¶
public int MaxRecordsToDraw { get; set; }
Property Value¶
FeatureSource¶
This property gets the FeatureSource for the FeatureLayer.
public FeatureSource FeatureSource { get; set; }
Property Value¶
FeatureSource
This property gets the FeatureSource for the FeatureLayer.
Remarks:
The FeatureSource is the provider of data to the FeatureLayer. There are different FeatureSource classes to match the various ways that feature data is stored. It is important that, when you inherit from the FeatureLayer, in the constructor you set the FeatureSource you want to use.
DrawingQuality¶
This property gets and sets the general drawing quality for the FeatureLayer's view.
public DrawingQuality DrawingQuality { get; set; }
Property Value¶
This property gets the general drawing quality for the FeatureLayer's
view.
Remarks:
The DrawingQuality enumeration allows you to control, in a macro sense, the drawing quality that will be used in the GeoCanvas. Each GeoCanvas, which is responsible for drawing of the features, may have its own specialized drawing quality properties. What the DrawingQuality enumeration does is define some general guidelines for each GeoCanvas. For example, if you set the DrawingQuality to HighSpeed, then inside of the PlatformGeoCanvas there is a profile for HighSpeed. This profile sets specific properties, such as the smoothing mode and composing drawing mode of the PlatformGeoCanvas. As each GeoCanvas may have different drawing quality properties, this offers a general way to control drawing quality and speed.
If you need complete control over how a specific GeoCanvas will draw, then you can set the DrawingQuality to Custom. This will tell the specific GeoCanvas to use the properties on its own object instead of one of the pre-defined profiles. If one of the profiles -- such as HighSpeed or HighQuality -- is set, then the specific GeoCanvas ignores its own properties for drawing quality.
ZoomLevelSet¶
This property gets and sets the ZoomLevelSet, which contains the specific zoom levels for the FeatureLayer.
public ZoomLevelSet ZoomLevelSet { get; set; }
Property Value¶
This property gets the ZoomLevelSet, which contains the specific zoom levels for
the FeatureLayer.
Remarks:
The ZoomLevelSet is a class that contains all of the ZoomLevels for the FeatureLayer. Each ZoomLevel contains the styles that are used to determine how to draw the InternalFeatures.
DrawingMarginInPixel¶
public float DrawingMarginInPixel { get; set; }
Property Value¶
Attribution¶
public string Attribution { get; set; }
Property Value¶
RequestDrawingInterval¶
public TimeSpan RequestDrawingInterval { get; set; }
Property Value¶
Name¶
This property gets and sets the name for the layer.
public string Name { get; set; }
Property Value¶
Remarks:
The name is user defined. It is useful to set, as it may be used for higher level components such as legends, etc.
IsOpen¶
This property returns true if the Layer is open and false if it is not.
public bool IsOpen { get; }
Property Value¶
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¶
This property gets and set the visible state of the layer.
public bool IsVisible { get; set; }
Property Value¶
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¶
This property gets the last drawing time for the layer.
public TimeSpan DrawingTime { get; protected set; }
Property Value¶
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¶
public DrawingExceptionMode DrawingExceptionMode { get; set; }
Property Value¶
Background¶
Gets and sets the background of the layer.
public GeoColor Background { get; set; }
Property Value¶
Transparency¶
This property gets and sets the amount of transparency to apply to the image.
public float Transparency { get; set; }
Property Value¶
Single
This property gets the amount of transparency to apply to the image.
Remarks:
None
BlueTranslation¶
This property gets and sets the amount of blue to apply to the image.
public float BlueTranslation { get; set; }
Property Value¶
Single
This property gets the amount of blue to apply to the image.
Remarks:
None
RedTranslation¶
This property gets and sets the amount of red to apply to the image.
public float RedTranslation { get; set; }
Property Value¶
Single
This property gets the amount of red to apply to the image.
Remarks:
None
GreenTranslation¶
This property gets and sets the amount of green to apply to the image.
public float GreenTranslation { get; set; }
Property Value¶
Single
This property gets the amount of green to apply to the image.
Remarks:
None
KeyColors¶
Gets a value represents a collection of key colors. If SupportKeyColor property is false, it will throw exception when you use KeyColors.
public Collection<GeoColor> KeyColors { get; }
Property Value¶
Remarks:
It will make these colors transparent when draw image.
IsNegative¶
This property gets and sets whether the image should be converted to negative (inverse colors).
public bool IsNegative { get; set; }
Property Value¶
Boolean
This property gets and sets whether the image should be converted to negative (inverse colors).
Remarks:
None
IsGrayscale¶
This property gets and sets if the image should be converted to grayscale.
public bool IsGrayscale { get; set; }
Property Value¶
This property gets and sets if the image should be converted to grayscale.
Remarks:
None
ThreadSafe¶
public ThreadSafetyLevel ThreadSafe { get; set; }
Property Value¶
ColorMappings¶
ColorMapping
public Dictionary<GeoColor, GeoColor> ColorMappings { get; }
Property Value¶
Dictionary<GeoColor, GeoColor>
WrappingMode¶
public WrappingMode WrappingMode { get; set; }
Property Value¶
WrappingExtent¶
public RectangleShape WrappingExtent { get; set; }
Property Value¶
Constructors¶
InMemoryFeatureLayer()¶
This is a constructor for the class.
public InMemoryFeatureLayer()
Remarks:
If you use this constructor, then you need to specify the FeatureSource column manually.
InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn>)¶
public InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn> featureSourceColumns)
Parameters¶
featureSourceColumns IEnumerable<FeatureSourceColumn>
InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn>, IEnumerable<Feature>)¶
This is a constructor for the class.
public InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn> featureSourceColumns, IEnumerable<Feature> features)
Parameters¶
featureSourceColumns IEnumerable<FeatureSourceColumn>
This parameter is the FeatureSourceColumn in this class that you want to use.
features IEnumerable<Feature>
This parameter represents the features in this class that you want to use.
Remarks:
This constructor gets the layer ready to use.
InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn>, IEnumerable<BaseShape>)¶
This is a constructor for the class.
public InMemoryFeatureLayer(IEnumerable<FeatureSourceColumn> featureSourceColumns, IEnumerable<BaseShape> shapes)
Parameters¶
featureSourceColumns IEnumerable<FeatureSourceColumn>
This parameter is the in this class that you want to use.
shapes IEnumerable<BaseShape>
This parameter represents the shapes in this class that you want to use.
Remarks:
This constructor gets the layer ready to use.
Methods¶
GetColumns()¶
This method returns the columns of data for the InternalFeatures in this Layer.
public Collection<FeatureSourceColumn> GetColumns()
Returns¶
Collection<FeatureSourceColumn>
Remarks:
You should set the column names for the data that the InternalFeatures will hold. For example, if you have some features that represent road signs, then one column you may want to add is "Sign Type". Then, for every Feature you add to the layer, you need to add the "Sign Type" and a value to the InternalFeatures' ColumnValues dictionary. If you provide this information, then you can use things like ValueStyles, Labeling, etc. based on the columns you have defined.
OpenCore()¶
This method opens the Layer so that it is initialized and ready to use.
protected void OpenCore()
Exceptions¶
InvalidOperationException
In the event you attempt to call this method on a Layer which has already been opened, it will throw an InvalidOperationException.
Remarks:
This abstract method is called from the concrete public method Open. The open method plays an important role, as it is responsible for initializing the Layer. Most methods on the Layer will throw an exception if the state of the Layer is not opened. When the map draws each layer, the layer will be opened as one of its first steps; then, after it is finished drawing with that layer, it will close it. In this way, we are sure to release all resources used by the Layer.
When implementing the abstract method, consider opening the FeatureSource or RasterSource. You will get a chance to close these in the Close method of the Layer.
BuildIndex()¶
This method build a spatial index for a passed group of featurs which increases access speed.
public void BuildIndex()
Clear()¶
This method will clear all the features included in the feature source.
public void Clear()
Exceptions¶
InvalidOperationException
If you attempt to call this method on a feature source which is in a transaction, it will throw an InvalidOperationException.
InvalidOperationException
If you attempt to call this method on a feature source which is not opened, it will throw an InvalidOperationException.
Events¶
DrawingFeatures¶
This event is raised when features are about to be drawn in the layer.
public event EventHandler<DrawingFeaturesEventArgs> DrawingFeatures;
Remarks:
This event is raised when features are about to be drawn in the layer. In the event arguments, there is a collection of features to be drawn. You can easily add or remove items from this collection so that extra items will draw or not draw.
DrawingWrappingFeatures¶
public event EventHandler<DrawingWrappingFeaturesFeatureLayerEventArgs> DrawingWrappingFeatures;
DrawingAttribution¶
public event EventHandler<DrawingAttributionLayerEventArgs> DrawingAttribution;
DrawnAttribution¶
public event EventHandler<DrawnAttributionLayerEventArgs> DrawnAttribution;
DrawingProgressChanged¶
public event EventHandler<DrawingProgressChangedEventArgs> DrawingProgressChanged;
RequestedDrawing¶
public event EventHandler<RequestedDrawingLayerEventArgs> RequestedDrawing;
RequestingDrawing¶
public event EventHandler<RequestingDrawingLayerEventArgs> RequestingDrawing;
DrawingException¶
public event EventHandler<DrawingExceptionLayerEventArgs> DrawingException;
DrawnException¶
public event EventHandler<DrawnExceptionLayerEventArgs> DrawnException;