ScaleBarAdornmentLayer¶
Namespace: ThinkGeo.Core
The ScaleBarAdornmentLayer class allows you show a bar graphic on the map that displays the distance scale for the current map extent.
public class ScaleBarAdornmentLayer : AdornmentLayer
Inheritance Object → Layer → AdornmentLayer → ScaleBarAdornmentLayer
Remarks:
Use the ScaleBarAdornmentLayer class as a quick way to implement a ScaleBar. When using the ScaleBarAdornmentLayer, you also need to add a ScaleLineAdornmentLayer to the map control. One thing we should pay attention to is that the ScaleBar will not be drawn when the CurrentExtent is outside of Range(-90,180,90,-180).
Properties¶
DisplayUnitString¶
This propery is a dictionary that exposes what text will be drawn to represent the ScaleLine Unit.
public Dictionary<string, string> DisplayUnitString { get; }
Property Value¶
Remarks:
We will display different letters for different units of measure; for example: "m" for meters, "ft" for feet, etc.
UnitFamily¶
Gets or sets the UnitSystem (Imperial/Metric) to be used for the ScaleBar.
public UnitSystem UnitFamily { get; set; }
Property Value¶
Remarks:
By setting this property, you can control whether to use a metric or imperial measurement system for the ScaleBar.
Thickness¶
Gets or sets the thickness of the ScaleBar. It is an integer value representing the height of the ScaleBar in screen units.
public int Thickness { get; set; }
Property Value¶
MaxWidth¶
Gets or Sets the MaxWidth of the ScaleBar.
public int MaxWidth { get; set; }
Property Value¶
Remarks:
You can use this property to set the maximum width that you want the ScaleBar to occupy on the map. The ScaleBarAdornmentLayer will automatically adjust its size based upon the current extent of the map. By setting this property, you can control the maximum width the ScaleBar will occupy on the map.
BarBrush¶
The property is the GeoBrush that will be used to draw the ScaleBar.
public GeoBrush BarBrush { get; set; }
Property Value¶
Remarks:
This BarBrush property will give you full control over the appearance of the ScaleBarAdornmentLayer.
TextStyle¶
public TextStyle TextStyle { get; set; }
Property Value¶
AlternateBarBrush¶
The property is the GeoBrush that will be used to draw the alternate ScaleBar.
public GeoBrush AlternateBarBrush { get; set; }
Property Value¶
Remarks:
This AlternateBarBrush property will give you full control over the appearance of the ScaleBarAdornmentLayer.
MaskBrush¶
Gets or sets the color for the ScaleBarAdornmentLayer's mask, if the HasMask property is set to true.
public GeoBrush MaskBrush { get; set; }
Property Value¶
HasMask¶
Gets or sets whether the ScaleBar will have a mask or not. A boolean value representing whether or not a mask is shown.
public bool HasMask { get; set; }
Property Value¶
Remarks:
Depending upon the look of your map and your requirements, you may or may not want a mask on the ScaleBar. You can control whether or not the ScaleBar has a mask by setting this property. If you set the HasMask property to true, be sure to specify a mask color (or texture) by using the MaskBrush property.
MaskContour¶
Gets or sets the pen for the outline of the ScaleBar mask.
public GeoPen MaskContour { get; set; }
Property Value¶
Remarks:
By using this property you can control the border of the mask, if the HasMask property is set to true. If you do not want a contour or border to show, you should set the pen to transparent.
BarPen¶
public GeoPen BarPen { get; set; }
Property Value¶
Width¶
public float Width { get; set; }
Property Value¶
Height¶
public float Height { get; set; }
Property Value¶
BackgroundMask¶
public AreaStyle BackgroundMask { get; set; }
Property Value¶
Location¶
This property gets and sets the drawing location of the AdornmentLayer.
public AdornmentLocation Location { get; set; }
Property Value¶
XOffsetInPixel¶
This property gets and sets the X pixel offset for the AdornmentLayer.
public float XOffsetInPixel { get; set; }
Property Value¶
Remarks:
This property allows you to specify an X offset. It is useful, when combined with a Y offset, to do things like modify the location of the adornment.
YOffsetInPixel¶
This property gets and sets the Y pixel offset for the AdornmentLayer.
public float YOffsetInPixel { get; set; }
Property Value¶
Remarks:
This property allows you to specify a Y offset. It is useful, when combined with an X offset, to do things like modify the location of the adornment.
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.
HasBoundingBox¶
This property indicates whether 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.
public bool HasBoundingBox { get; }
Property Value¶
Remarks:
The default value is false.
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.
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.
Attribution¶
public string Attribution { get; set; }
Property Value¶
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.
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
ColorMappings¶
ColorMapping
public Dictionary<GeoColor, GeoColor> ColorMappings { get; }
Property Value¶
Dictionary<GeoColor, GeoColor>
DrawingExceptionMode¶
Gets or sets the DrawExceptionMode when exception happens.
public DrawingExceptionMode DrawingExceptionMode { get; set; }
Property Value¶
ThreadSafe¶
public ThreadSafetyLevel ThreadSafe { get; set; }
Property Value¶
Projection¶
Gets the projection of the layer.
public Projection Projection { get; set; }
Property Value¶
Background¶
Gets and sets the background of the layer.
public GeoColor Background { get; set; }
Property Value¶
RequestDrawingInterval¶
public TimeSpan RequestDrawingInterval { get; set; }
Property Value¶
Constructors¶
ScaleBarAdornmentLayer()¶
Creates a new instance of the ScaleBarAdornmentLayer class.
public ScaleBarAdornmentLayer()
Remarks:
When displaying a ScaleBarAdornmentLayer, we need to instance a ScaleLineAdornmentLayer and add it to MapEngine. The ScaleBar will not be drawn when the CurrentExtent is outside of the world Extent(-90,180-,90,-180).
Methods¶
OpenCore()¶
protected void OpenCore()
CloseCore()¶
protected void CloseCore()
UpdateScale(GeoCanvas, GeographyUnit)¶
internal void UpdateScale(GeoCanvas canvas, GeographyUnit mapUnit)
Parameters¶
canvas GeoCanvas
mapUnit GeographyUnit
DrawCore(GeoCanvas, Collection<SimpleCandidate>)¶
This method draws the Layer.
protected void DrawCore(GeoCanvas canvas, Collection<SimpleCandidate> labelsInAllLayers)
Parameters¶
canvas GeoCanvas
This parameter is the view object or a NativeImage to draw on.
labelsInAllLayers Collection<SimpleCandidate>
This parameter represents the labels used for collision detection and duplication
checking.
Remarks:
This abstract method is called from the concrete public method Draw. This method draws the representation of the layer based on the extent you provided.
When implementing this abstract method, consider each feature and its column data values. You can use the full power of the GeoCanvas to do the drawing. If you need column data for a feature, be sure to override the GetRequiredColumnNamesCore and add the columns you need to the collection. In many of the styles, we add properties to allow the user to specify which field they need; then, in the GetRequiredColumnNamesCore, we read that property and add it to the collection.
Events¶
DrawingProgressChanged¶
public event EventHandler<DrawingProgressChangedEventArgs> DrawingProgressChanged;
DrawingException¶
public event EventHandler<DrawingExceptionLayerEventArgs> DrawingException;
DrawnException¶
public event EventHandler<DrawnExceptionLayerEventArgs> DrawnException;
DrawingAttribution¶
public event EventHandler<DrawingAttributionLayerEventArgs> DrawingAttribution;
DrawnAttribution¶
public event EventHandler<DrawnAttributionLayerEventArgs> DrawnAttribution;
RequestedDrawing¶
public event EventHandler<RequestedDrawingLayerEventArgs> RequestedDrawing;
RequestingDrawing¶
public event EventHandler<RequestingDrawingLayerEventArgs> RequestingDrawing;