Table of Contents

Class IconStyle

Namespace
ThinkGeo.Core
Assembly
ThinkGeo.Core.dll

This class displays an icon with text from the data of the feature.

public class IconStyle : TextStyle
Inheritance
IconStyle
Inherited Members

Remarks

You can use the IconStyle when you have an icon you want to display on the map with characters inside of that icon. For example, if you have a circular icon and you want to label the number 1-100 inside of the icon, you can use this class. You need to specify the column name where the numbers or letters will come from, as well as a font. Through various properties, you can also control the positioning of the icon, just as you would with the TextStyle.

Constructors

IconStyle()

This is the constructor for the class.

public IconStyle()

Remarks

If you use this, then you should set the properties manually -- such as the column name, font, solid brush and the image.

IconStyle(string, string, GeoFont, GeoBrush)

This is the constructor for the class.

public IconStyle(string iconPathFilename, string textColumnName, GeoFont textFont, GeoBrush textBrush)

Parameters

iconPathFilename string

This parameter is the path and filename of the icon you want to use.

textColumnName string

This parameter is the column name from which to get the data for the text.

textFont GeoFont

This parameter is the font used to draw the text on the icon.

textBrush GeoBrush

This parameter is the solid brush that is used to draw the text on the icon.

Remarks

This constructor allows you to pass in the path to the icon, along with the column name, font and solid brush to use. This is the most commonly used constructor. If you need to use an image from a stream, then you should use the constructor that takes a NativeImage.

IconStyle(GeoImage, string, GeoFont, GeoBrush)

This is the constructor for the class.

public IconStyle(GeoImage iconImage, string textColumnName, GeoFont textFont, GeoBrush textBrush)

Parameters

iconImage GeoImage

This parameter is the image to use in this style.

textColumnName string

This parameter is the column name from which to get the data for the text.

textFont GeoFont

This parameter is the font used to draw the text on the icon.

textBrush GeoBrush

This parameter is the solid brush that is used to draw the text on the icon.

Remarks

This constructor allows you to use a NativeImage instead of specifying a path and filename of the icon. This is commonly used if the image comes from a stream.

Properties

IconImage

This property gets and sets the NativeImage you want to use for the image.

public GeoImage IconImage { get; set; }

Property Value

GeoImage

This property gets the NativeImage you want to use for the image.

Remarks

You will typically want to use this property if your image is derived from a stream. Otherwise, you can use the IconFilePathName property to specify where the icon is located and we will handle the rest.

IconImageScale

This property gets and sets the scale of the image you want to draw.

public double IconImageScale { get; set; }

Property Value

double

This property gets the scale of the image you want to draw.

Remarks

This property allows you to scale the image up and down depending on how large or small you want it. It can be changed dynamically, so you could change it at every scale level to resize the bitmap based on the current scale. A scale of 1 would be the original size, while a scale of 2 would double the size. A scale of .5 would reduce the size of the image by half, and so on.

IconPathFilename

This property gets and sets the filename and path for the image you want to use in the style.

public string IconPathFilename { get; set; }

Property Value

string

This property gets the filename and path for the image you want to use in the style.

Remarks

You can also optionally use the IconImage property if the image you want to use is derived from a stream.

SuppressPartialLabels

This property gets and sets whether a partial label in the current extent will be drawn or not.

public bool SuppressPartialLabels { get; set; }

Property Value

bool

Remarks

This property provides a solution to the "cut off" label issue in Map Suite Web Edition and Desktop Edition, which occurs when multiple tiles exist. When you set this property to true, any labels outside of the current extent will not be drawn.

Methods

DrawCore(IEnumerable<Feature>, GeoCanvas, Collection<SimpleCandidate>, Collection<SimpleCandidate>)

This method draws the features on the view you provided.

protected override void DrawCore(IEnumerable<Feature> features, GeoCanvas canvas, Collection<SimpleCandidate> labelsInThisLayer, Collection<SimpleCandidate> labelsInAllLayers)

Parameters

features IEnumerable<Feature>

This parameter represents the features you want to draw on the view.

canvas GeoCanvas

This parameter represents the view you want to draw the features on.

labelsInThisLayer Collection<SimpleCandidate>

The labels will be drawn in the current layer only.

labelsInAllLayers Collection<SimpleCandidate>

The labels will be drawn in all layers.

Remarks

This overridden method is called from the concrete public method Draw. In this method, we take the features you passed in and draw them on the view you provided. Each style (based on its properties) may draw each feature differently.


When overriding this 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.

Exceptions

InvalidOperationException

In the event you attempt to call this method when the GeoCanvas's IsDrawing mode is false, it will throw an InvalidOperationException.

ArgumentNullException

If you pass a null as the view, we will throw an ArgumentNullException.

ArgumentNullException

If you pass a null as the features, we will throw an ArgumentNullException.

DrawSampleCore(GeoCanvas, DrawingRectangleF) 

protected override void DrawSampleCore(GeoCanvas canvas, DrawingRectangleF drawingExtent)

Parameters

canvas GeoCanvas
drawingExtent DrawingRectangleF

GetLabelingCandidateCore(Feature, GeoCanvas, GeoFont, float, float, double)

This method determines which labels will be candidates for drawing.

protected override Collection<LabelingCandidate> GetLabelingCandidateCore(Feature feature, GeoCanvas canvas, GeoFont font, float xOffsetInPixel, float yOffsetInPixel, double rotationAngle)

Parameters

feature Feature

This parameter represents the features you want to draw on the view.

canvas GeoCanvas

This parameter represents the view you want to draw the features on.

font GeoFont
xOffsetInPixel float
yOffsetInPixel float
rotationAngle double

Returns

Collection<LabelingCandidate>

This method returns a collection of labeling candidates.

Remarks

This overridden method is called from the concrete public method GetLabelingCandidate. In this method, we determine if the feature passed in will be a candidate for drawing. If you have the grid method enabled, then we determine this by ensuring that only one label will be eligible per grid cell. In this way, we can ensure that labels always draw in the same place at the same scale.

Exceptions

ArgumentNullException

If you pass a null as the view, we will throw an ArgumentNullException.

InvalidOperationException

In the event you attempt to call this method when the GeoCanvas's IsDrawing mode is false, it will throw an InvalidOperationException.