SqliteFeatureLayer¶

Namespace: ThinkGeo.Core

This class represents a FeatureSource backed by SQLite.

public class SqliteFeatureLayer : FeatureLayer

Inheritance Object → LayerBase → Layer → FeatureLayer → SqliteFeatureLayer

Remarks:

None

Properties¶

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 SqliteFeatureLayer, we override this API and mark it as true.

public bool HasBoundingBox { get; }

Property Value¶

Boolean

Remarks:

The default implementation in the base class returns false.

CommandTimeout¶

public int CommandTimeout { get; set; }

Property Value¶

Int32

ConnectionString¶

This property gets and sets the connection string used to connect to the server.

public string ConnectionString { get; set; }

Property Value¶

String
This property gets the connection string used to connect to the server.

Remarks:

None

TableName¶

This property gets or sets the table name the database will use.

public string TableName { get; set; }

Property Value¶

String
This property gets the table name the database will use.

Remarks:

None

FeatureIdColumn¶

This property gets or sets the name of the column that holds the unique feature Id.

public string FeatureIdColumn { get; set; }

Property Value¶

String

        This property gets the name of the column that holds the unique feature
        Id.

Remarks:

None

GeometryColumnName¶

public string GeometryColumnName { get; set; }

Property Value¶

String

WhereClause¶

public string WhereClause { get; set; }

Property Value¶

String

Projection¶

public Projection Projection { get; }

Property Value¶

Projection

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¶

EditTools

        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¶

Collection<String>

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¶

QueryTools

        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¶

Int32

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¶

DrawingQuality

        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¶

ZoomLevelSet

        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¶

Single

Attribution¶

public string Attribution { get; set; }

Property Value¶

String

RequestDrawingInterval¶

public TimeSpan RequestDrawingInterval { get; set; }

Property Value¶

TimeSpan

Name¶

This property gets and sets the name for the layer.

public string Name { get; set; }

Property Value¶

String

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¶

Boolean

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¶

Boolean

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¶

TimeSpan

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¶

DrawingExceptionMode

Background¶

Gets and sets the background of the layer.

public GeoColor Background { get; set; }

Property Value¶

GeoColor

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¶

Collection<GeoColor>

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¶

Boolean

        This property gets and sets if the image should be converted to grayscale.

Remarks:

None

ThreadSafe¶

public ThreadSafetyLevel ThreadSafe { get; set; }

Property Value¶

ThreadSafetyLevel

ColorMappings¶

ColorMapping

public Dictionary<GeoColor, GeoColor> ColorMappings { get; }

Property Value¶

Dictionary<GeoColor, GeoColor>

WrappingMode¶

public WrappingMode WrappingMode { get; set; }

Property Value¶

WrappingMode

WrappingExtent¶

public RectangleShape WrappingExtent { get; set; }

Property Value¶

RectangleShape

Constructors¶

SqliteFeatureLayer()¶

This is the constructor for the class.

public SqliteFeatureLayer()

SqliteFeatureLayer(String, String, String, String)¶

This is the constructor for the class.

public SqliteFeatureLayer(string connectionString, string tableName, string featureIdColumn, string geometryColumnName)

Parameters¶

connectionString String
This parameter represents the connection string to connect to the server.

tableName String
This parameter represents the table name being accessed.

featureIdColumn String

        This parameter represents the name of the column that holds the unique feature
        Id.

geometryColumnName String

Remarks:

None

SqliteFeatureLayer(SqliteConnection, String, String, String)¶

public SqliteFeatureLayer(SqliteConnection connection, string tableName, string featureIdeColumn, string geometryColumnName)

Parameters¶

connection SqliteConnection

tableName String

featureIdeColumn String

geometryColumnName String

Methods¶

GetFirstGeometryType()¶

public WellKnownType GetFirstGeometryType()

Returns¶

WellKnownType

ExecuteNonQuery(String)¶

This method executes a query that does not return a SQL result.

public int ExecuteNonQuery(string sqlStatement)

Parameters¶

sqlStatement String
This parameter represents the SQL statement that will be executed.

Returns¶

Int32
The number of records effected.

Remarks:

This methods executes a query that has no results.

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;