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map_suite_desktop_edition_faq_layers_featuresources

Map Suite Desktop Edition FAQ Layers & FeatureSources

How do I efficiently display a subset of a shape file without splitting it?

This question has a corresponding sample application(s) associated with it.

Sample: Build Custom Shapefile Indexes

This sample shows how you can display a subset of a shapefile without splitting the physical shapefile. For example, you may have a single shapefile that contains both highways and local roads. To improve display speed, you may be temped to split it into two separate shapefiles so you can quickly display local roads with one style and highways with another style (and avoid using a value style, which can be slow). But at this project demonstrates, rather than split your shapefile you can simply build two custom indexes, one for each road type. Then, when you create your ShapeFileFeatureLayer, you'll simply use your original shapefile and specify a custom index. Each custom index will limit the records that can be seen by the Layer, making it very fast and efficient.

For more information and a real-world example, please see the Map Suite discussion forum post at: Forum Post

How do I display highways and local roads using different symbols from the same shape file?

This question has a corresponding sample application(s) associated with it.

Sample: Build Custom Shapefile Indexes

This sample shows how you can display a subset of a shapefile without splitting the physical shapefile. For example, you may have a single shapefile that contains both highways and local roads. To improve display speed, you may be temped to split it into two separate shapefiles so you can quickly display local roads with one style and highways with another style (and avoid using a value style, which can be slow). But at this project demonstrates, rather than split your shapefile you can simply build two custom indexes, one for each road type. Then, when you create your ShapeFileFeatureLayer, you'll simply use your original shapefile and specify a custom index. Each custom index will limit the records that can be seen by the Layer, making it very fast and efficient.

For more information and a real-world example, please see the Map Suite discussion forum post at: Forum Post

Is there something faster than the ValueStyle?

This question has a corresponding sample application(s) associated with it.

Sample: Build Custom Shapefile Indexes

This sample shows how you can display a subset of a shapefile without splitting the physical shapefile. For example, you may have a single shapefile that contains both highways and local roads. To improve display speed, you may be temped to split it into two separate shapefiles so you can quickly display local roads with one style and highways with another style (and avoid using a value style, which can be slow). But at this project demonstrates, rather than split your shapefile you can simply build two custom indexes, one for each road type. Then, when you create your ShapeFileFeatureLayer, you'll simply use your original shapefile and specify a custom index. Each custom index will limit the records that can be seen by the Layer, making it very fast and efficient.

For more information and a real-world example, please see the Map Suite discussion forum post at: Forum Post

How do I draw a north arrow on my map?

This question has a corresponding sample application(s) associated with it.

Sample:Compass

In the project “North Arrow”, you saw how to extend AdornmentLayer to create a North Arrow AdormentLayer. In this project, we expand on that idea and create a more sophisticated class. You will see how you can combine two images to create a compass. Compare to “North Arrow” project, we also added some other handy properties such as a Position property. Also, the compass can be of varied sizes thanks to the SizePercentage property. Finally, if you pass just one image, the compass can behave just like a regular north arrow.

We also added new designs of compass in smaller version. See the attached file: Rotating Compass New Smaller Designs.zip.

How do I display graphs and charts on the map?

This question has a corresponding sample application(s) associated with it.

Sample:Zedgraph

In our “How Do I” apps, there is sample app that shows how to add graphs to the map using the ZedGraph library. In this project, using the same data, the US cities, we elaborate a little bit on the pie chart. You will see how to add some gradient colors to the chart, how to label the different pie slices, how to add a title etc. Zedgraph is a truly massive library for graphics and Pie chart is only one type of chart among many others. As you can add pie charts to your map, you can also add bar charts, trend charts etc. I suggest you check out this site for more info on ZedGraph

http://zedgraph.org/wiki/index.php?title=Main_Page

With Map Suite, you have the whole ZedGraph API available with an easy interface to add the graphs to the map.

For this project, in addition to the MapSuiteCore.dll, you will also need the ZedGraph.dll and ZedGraphStyleExtension.dll references. We will have several projects showing how to integrate other types of charts to your map.

How do I add a watermark to the map?

This question has a corresponding sample application(s) associated with it.

Sample:Watermark Adornment Layer

This project shows how to create a WaterMarkAdornmentLayer class inheriting from AdormentLayer. Notice that in the overridden method DrawCore, the drawing is done using screen coordinates. This is a characteristic of Adornment Layer and any layer inheriting from it. In this example, the code in the DrawCore method places the water mark text at regular interval but you could easily modify the code to have the water mark text placed randomly on the map. Notice that WaterMarkAdornmentLayer is added to the StaticLayers collection of the MapEngine meaning that you can place this adornment layer on top of all the other layers or between any other layers. This class is useful for providing demos to clients.

How do I encrypt a shape file for security?

This question has a corresponding sample application(s) associated with it.

Sample:Shapefile Encryption

In today’s project, we are looking at a way to encrypt shapefiles to prevent them from being used outside the application. We show how to encrypt and decrypt shapefiles using streams. You will see that a very simple encryption algorithm is used but by looking at the example, you will be able to implement your own. Disclaimer: This encryption system can be used only on small shapefiles due to the amount of memory used. A typical use would be to encrypt some valuable small shapefiles you don't want your users to access. In the future, Map Suite will provide a full encryption system as an API.

How do I get geometry data from the server using WCF in Silverlight?

This question has a corresponding sample application(s) associated with it.

Sample:Get Data From Server With WCF

In this Silverlight-based project, we are going to take a look at how to get geometry data from the server side using the WCF service with Map Suite Silverlight Edition, while keeping all map data on the server side. You can click any of the countries on the map to call a WCF service, which will require data from the server, and then a popup will appear with information about that country.

How do I display a scale bar using custom units?

This question has a corresponding sample application(s) associated with it.

Sample:Scale Bar

Map Suite already offers classes such as ScaleBarAdornmentLayer for displaying scale bars on the map but they are limited to certain common units like meters, kilometers, feet and miles. In this project, you are going to learn the basics for creating a scale bar using the unit of your choice. The class CustomUnitScaleBar displays a very simple scale bar but you will find the logic for basics of creating a scale bar. Looking at the code, you will be able to create more sophisticated stylish scale bars for your own needs.

How can I show my own logo on the map?

This question has a corresponding sample application(s) associated with it.

Sample:Graphic Logo Adornment Layer

This sample shows how you can display your logo on the map using an AdornmentLayer. The advantage of using an Adornment is that the graphic stays in place and doesn't move as you pan your map. The sample should work for various kinds of logos and allow you to change the position using the AdornmentLayer's properties.

How do I display heat map?

This question has a corresponding sample application(s) associated with it.

Sample:Heat Map

Heat maps is a technique increasingly used in various fields such in biology and other fields See http://en.wikipedia.org/wiki/Heat_map. They are also used for displaying areas of webs page most frequently scanned by users. http://csscreme.com/heat-maps/. At ThinkGeo, we are taking this concept to GIS and applying it to geographic maps. Heat maps are a great way to give the users a visually compelling representation of the distribution and intensity of geographic phenomenon. For that purpose, we are releasing a new extention called MapSuiteHeatMapExtension. We invite you to try this out extension with your own data and give us feed back on it before we release it to our core products. Today, we are posting two Desktop projects on that subject. The first one is using the swine flu data we used in an earlier project. You can see how powerful the visualization of that data is to show the spatial distribution flu swine cases. In the next project, you will see how to take into account column values to produce various degrees of intensity using some earthquake data. In those two projects, you will need references to MapSuiteCore.dll, DesktopEdition.dll, WorldMapKitWms.dll (Evaluation or full versions) and MapSuiteHeatMapExtension.dll (included in the zip file).

Sample:Heat Map with earthquakes

After the project on displaying swine flu data using the heat map technique, here you learn how to apply parameters other than strictly spatial distribution to affect the coloring of the map.

In this example, the magnitude of each earthquake (from 0 to 12) is taken into account to influence the displaying of the heat map. The result is California appearing even more intense than if only the spatial distribution were taken into account. As for the previous project, you will need references to MapSuiteCore.dll, DesktopEdition.dll, WorldMapKitWms.dll (Evaluation or full versions) and MapSuiteHeatMapExtension.dll (included in the zip file). As a caveat on heat map in GIS, it is worth mentioning that while this is great tool for displaying data in a very appealing and communicative way, it cannot be used as an analysis tool for studying spatial behaviors. For spatial analysis, GRID is the appropriate tool. Although a heat map looks like a GRID, it is not one and it cannot substitute GRID for spatial analysis.

How can I load an image from a stream rather than a file?

This question has a corresponding sample application(s) associated with it.

Sample:Image Stream Loading

As an alternative to loading an Image with the image file from the file system, you can choose to pass your own stream. This project shows you how to use the event StreamLoading of GdiPlusRasterSource for this purpose. In this project, we show how to do this using a Tiff image but you can also use that event for ShapeFileFeatureSource as we show in a previous project “Shapefile Encryption”. Keep in mind that this technique only works with images besides MrSid, ECW and Jpeg2000. These types of images do not work because the providers do not support streams in their decoding SDKs.

How can I draw KML on the map?

This question has a corresponding sample application(s) associated with it.

Sample:KML Extension

KML is the file format for displaying geographic data in a Google Earth browser such as Google Earth. Now, you can also display such a file on a Map Suite control. Thanks to its flexible architecture to extent to new file formats, in today’s project we wrote the logic for supporting KML. Look at the class KmlfeatureSource inheriting from FeatureSource to see how the logic for reading FML files was implemented. As well, you can see the class KmlStyle inheriting from Style for the drawing logic. And feel free to modify and improve those classes with your own implementations.

How do I display latitude and longitude graticule lines?

This question has a corresponding sample application(s) associated with it.

Sample:Latitude Longitude Graticule

After the projects on North Arrow and Compass, we created another project related to Adornment Layer to have a more stylish map and give more information to the user navigating the map.

In this project, we create a Graticule Adorment Layer that shows Meridians and Parallels displaying through the map. Meridians are lines of longitude and they have a North South orientation. Parallels are lines of latitude and they have an East West orientation. Showing graticule for latitude and longitude is a standard way in cartography to give spatial references to the users. You will find two zip files. One is for the Desktop Edition “LatLongGraticule” and it shows nicely the effect of the meridians and parallels as you pan and zoom in and out. You will also see, as additional spatial references to the users, the latitude and longitude location at the mouse pointer in labels at the mouse move event. You will see that information in the decimal degrees format and in the Degrees Minutes Seconds format. For those that don’t have the Desktop Edition, you will find the zip file “LatLongGraticuleServices” for the Service edition. It is using exactly the same GraticuleAdormentLayer class. In the future, we will offer another class for graticule with more options for formatting and displaying the graticule. It will also offer projection support for map that are not in Decimal Degrees map unit.

How can I display a legend on my map?

This question has a corresponding sample application(s) associated with it.

Sample:Legend Adornment Layer

Following inquiries on how to show a legend on the map in the discussion Forum, we decided to post a project on that topic in the Code Community. In this project, you will find the class LegendAdornmentLayer which shows the basics of displaying the symbols for each layer belonging to each Overlay of the Map. Looking at the code, you will understand how to extend that class and build a more sophisticated Legend on your own.

How do I display point data from an OLE DB complied data source?

This question has a corresponding sample application(s) associated with it.

Sample:Oledb Point FeatureSource

This project shows the power of MapSuite by giving to the developer the possibility to create its own layer based on an existing format containing spatial information. If the developer is familiar with a certain format like oledb, he can create its own FeatureSource reading the database and its own FeatureLayer wrapping the FeatureSource and providing the drawing logic.

In this project, we create the class OledbPointFeatureSource inheriting from FeatureSource and OledbPointFeatureLayer inheriting from FeatureSource.

How do I create a numbered grid for a given extent?

This question has a corresponding sample application(s) associated with it.

Sample:Numbered Grid

In many atlases, you can see maps with a numbered grid to give the page reference for a more detailed map. In today’s project, we show how to construct such a grid. Based on the extent of the feature, the number of columns and rows, a grid can be created with the page number in each cell.

How do I draw a north facing arrow when using rotation?

This question has a corresponding sample application(s) associated with it.

Sample:North Arrow

This project demonstrates basically two techniques; How to rotate a map and how to have a North Arrow keeping the right north orientation. Rotating the map:

To rotate the map, you have to be aware that you have to use RotationProjection class provided by MapSuite API. All the layers need to have their projection property set to RotationProjection. Beware that if a Layer does not have that property set, it will not rotate along with the rest of the map.

Displaying the North Arrow:

As the map rotate, it is important to keep track of the orientation of the map and to know what the direction to the North is. Inheriting from Adornment Layer, RotatingAdornmentLayer class takes an Image representing a North Arrow and with its RotateAngle property set according to the angle property of RotationProjection, it always shows the North correctly.

How do I work with multi index files?

This question has a corresponding sample application(s) associated with it.

Sample:Multi Index

Today our purpose is to gather into one concise project all the different knowledge we learned about multi index in various Discussion Forum posts such as: http://gis.thinkgeo.com/Support/DiscussionForums/tabid/143/aff/21/aft/5921/afv/topic/Default.aspx http://gis.thinkgeo.com/Support/DiscussionForums/tabid/143/aff/21/aft/5958/afv/topic/Default.aspx Consolidating various physical shapefiles into one layer is a flexible and clean way to handle your data. Thanks to multi index, you can treat your layers as one. Depending on your needs you can choose to use all the shapefiles in one folder or only a few. In this project you will see the different ways to use the powerful static function MultipleShapeFileFeatureLayer.BuildIndex()

How to use a common FeatureSource for two different Overlays?

This question has a corresponding sample application(s) associated with it.

Sample:Combining Overlays

In today’s Wpf project, we show a technique of using a common FeatureSource for two different Overlays. From a physical shapefile representing cities, a regular LayerOverlay is used for the higher zoom levels while a FeatureSourceMarkerOverlay is used for the lower zoom levels. FeatureSourceMarkerOverlay is a Wpf specific overlay offering features for a better user experience such a Tooltips and ImageSource.

How to edit the geometry of a shapefile?

This question has a corresponding sample application(s) associated with it.

Sample:Edit Geometry Of Shapefile

The purpose of this sample is to show how to update the geometry of a feature of a shapefile in one step. This sample is useful for anyone wanting to actualize the geometry part of its data. You can see how only a few lines of code are necessary for this process and that the spatial index gets automatically updated after calling the committing the change. Notice that this sample does not show all the fanciness for manipulating at user interaction the geometry to be updated. For this purpose, you can see all the samples related to TrackInteractiveOverlay and EditInteractiveOverlay.

How to edit attribute of a shapefile?

This question has a corresponding sample application(s) associated with it.

Sample:Edit Attribute Of Shapefile

The purpose of this Wpf sample is to show how to edit the attribute of a feature of a shapefile. This sample is useful for anyone wanting to actualize the attribute part of its data by simply clicking on the desired feature on the map and updating its attribute in a textbox. You will find the editing part of the code in the KeyDown event of the textbox.

How to create GRID?

This question has a corresponding sample application(s) associated with it.

Sample:Create GRID

Today’s sample shows the new feature available in this may release Map Suite 5 for creating GRID files. A GRID is a raster format that defines a geographic space as an array of equally sized squares (cells) arranged in rows and columns. Each cell stores a numeric value that represents an attribute (such as elevation, surface slope, soil pH etc.) for that unit of space. Each GRID cell is referenced by its x, y coordinate location. Typically a GRID file is created based on some sample points with known values. In today’s sample, we take the example of creating a GRID file based on a point based shapefile representing soil pH values of some sample locations in a field. Using the Inverse Weighted Distance algorithm for interpolation, we create the GRID with the pH value for the entire extent of the field. Look at the code and comments for more details on how GRID files get generated and displayed on the map. This sample is a Desktop application but GRID can be used in all the editions of Map Suite.

Can I create isolines (a.k.a. contour lines) with Map Suite?

This question has a corresponding sample application(s) associated with it.

Sample:Isolines

Yes. Starting with build 5.0.87.0 of Map Suite, you can add isolines to your applications with Map Suite – please see the code sample linked above. For the uninitiated, isolines are a way to visualize breaks between different groups of data such as elevation levels, soil properties, or just about anything else you can imagine. The above code sample also shows the various steps in creating isolines, including the gathering of point data, creating a grid using interpolation, and finally, picking your isoline break levels. We also quickly dive into some more advanced options such as generating isolines on the fly. To bring this all together, check out our instructional video that will walk you through the process of setting up and working with isolines in Map Suite.

map_suite_desktop_edition_faq_layers_featuresources.txt · Last modified: 2015/09/15 06:28 by admin