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ThinkGeo Quick Start Guide For Blazor

The ThinkGeo UI Web for Blazor Quickstart Guide will guide you through the process of creating a sample blazor serverside application and will help you become familiar with ThinkGeo Products. The Quickstart Guide supports ThinkGeo UI Web for Blazor 12.0 and higher and will show you how to create an ASP.NET Core Blazor application.

ThinkGeo UI Web for Blazor is a full-featured mapping control that makes it easy for any Microsoft .NET developer to add mapping functionality to a ASP.NET Core Blazor application quickly and efficiently. Using the intuitive object model, even developers inexperienced in Geographic Information Systems (GIS) can have fully functional maps working in minutes.

How do we start to learn how to take advantage of the power of ThinkGeo UI Web for Blazor? The best way is to make a sample application with it.

Download the Sample

Setting up the Environment

Get started with Blazor, you need .NET Core 3.0 and Visual Studio 2019 Preview. More information please refer to Get started with ASP.NET Core Blazor. (NOTE: ThinkGeo UI Web for Blazor only support server-side of Blazor currently, In this guide we are just using Blazor serverside as an example.)

Let's create a Blazor project after the environment is installed. Also you can run the project you just downloaded.

  1. Open Visual Studio 2019 Preview
  2. Create a New Project
  3. Select Blazor App. Select Next.
  4. Type project name as 'QuickStart' in the Project name field or accept the default project name. Confirm the Location entry is correct or provide a location for the project. Select Create.
  5. For ThinkGeo UI Web for Blazor, choose the Blazor Server App template. Select Create.
  6. Press F5 to run the app, you can see the browser is launched as following:

Now, you successfully created a native blazor serverside sample. See Get started with ASP.NET Core Blazor, If there are any issue during running this sample.

Installing ThinkGeo UI Web for Blazor NuGet packages

To build this sample, you need to reference the component package from NuGet Manager. NuGet brings us a flexible way and pleasant experience to manage our references.

  1. Right-click on the project in the solution and select Manage NuGet Package:
  2. Search the packages named 'ThinkGeo.UI.Blazor' list above and install it.
  3. Now the package is installing into the project. Click “OK” if the message box like the following pops up.

Add the Map Component

Now, we have all the references set. let's start by writing code step by step to display a world map with Shapefile.

Display a world map

1. Add the following code snippet to ~/_imports.razor file to reference ThinkGeo.UI.Blazor into all components in this project:

  @using ThinkGeo.Core
  @using ThinkGeo.UI.Blazor

2. Open the ~/Pages/_host.cshtml file in the blazor project. Register the stylesheet and javascript of ThinkGeo Web For Blazor from CDN:

  <head>
      ...
      <link href="https://cdn.thinkgeo.com/blazor/1.0.0/blazor.css" rel="stylesheet" />
  </head>
  
  <body>
      ...
      <script src="https://cdn.thinkgeo.com/blazor/1.0.0/blazor.js"></script>
  </body>

3. Open ~/wwwroot/css/site.css file and add the following stylesheet for demomap which is the element Id of map in this sample.

  #demomap {
      width:600px;
      height:500px;
  }

4. Open ~/Pages/Index.razor file and Add a ThinkGeo.UI.Blazor.Map component at the end as following:

  @page "/"
  
  <h1>Hello, world!</h1>
  
  Welcome to your new app.
  <Map Id="demomap" @ref="map" Background="@background"
       MapUnit="@ThinkGeo.Core.GeographyUnit.Meter"
       Center="@(new PointShape(-11067139.908560446, 5855996.337964549))"
       Zoom="3">
      <OverlaysSetting>
          <LayerOverlay Id="CustomOverlay" Layers="@layers"></LayerOverlay>
      </OverlaysSetting>
      <MapToolsSetting>
          <MapTools>
              <ZoomBarMapTool />
          </MapTools>
      </MapToolsSetting>
  </Map>
  
  @code{
      GeoSolidBrush background = new GeoSolidBrush(GeoColor.FromHtml("#89d3f0ff"));
      GeoCollection<Layer> layers = new GeoCollection<Layer>();
      Map map;
  
      protected override void OnInitialized()
      {
          // We create a new Layer and pass the path to a ShapeFile into its constructor.
          ShapeFileFeatureLayer worldLayer = new ShapeFileFeatureLayer("./Data/countries/countries.shp");
          worldLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
          
          // Set the worldLayer to use a preset Style.
          AreaStyle areaStyle = new AreaStyle();
          areaStyle.FillBrush = new GeoSolidBrush(GeoColor.FromArgb(255, 233, 232, 214));
          areaStyle.OutlinePen = new GeoPen(GeoColor.FromArgb(255, 118, 138, 69), 1);
          areaStyle.OutlinePen.DashStyle = LineDashStyle.Solid;
          worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = areaStyle;
          
          // This setting will apply from ZoomLevel01 to ZoomLevel20, which means we can see the world the same style all the time no matter how far we zoom in or out.
          worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
          
          // We need to add the worldLayer to the LayerOverlay in the map.
          layers.Add(worldLayer);
      }
  }
  

we'll use a ShapeFile containing data of the entire world. We have one such ShapeFile available to us:

  • The borders of every country in the world (countries.shp)

(NOTE: The data used in this sample can be found in the attached sample above at “./Data/countries” folder)

Run the App by pressing F5. If you have not set up a developer license, the Map Suite Product Center will pop up. You will need to generate your developer license. For more details, please refer to http://wiki.thinkgeo.com/wiki/map_suite_developer_license_guide.

Once the developer license is ready, run the application. Your map should look like the one below:

Add PointStyle for the capitals of the world countries

Add a ShapeFileFeatureLayer with PointStyle for Capitals in method “OnInitialized”.

  protected override void OnInitialized()
  {
      // We create a new Layer and pass the path to a ShapeFile into its constructor.
      ShapeFileFeatureLayer worldLayer = new ShapeFileFeatureLayer("./Data/countries/countries.shp");
      worldLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
  
      // Set the worldLayer to use a preset Style.
      AreaStyle areaStyle = new AreaStyle();
      areaStyle.FillBrush = new GeoSolidBrush(GeoColor.FromArgb(255, 233, 232, 214));
      areaStyle.OutlinePen = new GeoPen(GeoColor.FromArgb(255, 118, 138, 69), 1);
      areaStyle.OutlinePen.DashStyle = LineDashStyle.Solid;
      worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = areaStyle;
  
      // This setting will apply from ZoomLevel01 to ZoomLevel20, which means we can see the world the same style all the time no matter how far we zoom in or out.
      worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
  
      // We need to add the worldLayer to the LayerOverlay in the map.
      layers.Add(worldLayer);
  
      ShapeFileFeatureLayer capitalLayer = new ShapeFileFeatureLayer("./Data/capitals/WorldCapitals.shp");
      capitalLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
  
      PointStyle pointStyle = new PointStyle();
      pointStyle.SymbolType = PointSymbolType.Square;
      pointStyle.FillBrush = new GeoSolidBrush(GeoColors.White);
      pointStyle.OutlinePen = new GeoPen(GeoColors.Black, 1);
      pointStyle.SymbolSize = 6;
  
      PointStyle stackStyle = new PointStyle();
      stackStyle.SymbolType = PointSymbolType.Square;
      stackStyle.FillBrush = new GeoSolidBrush(GeoColors.Maroon);
      stackStyle.OutlinePen = new GeoPen(GeoColors.Transparent, 0);
      stackStyle.SymbolSize = 2;
  
      pointStyle.CustomPointStyles.Add(stackStyle);
      capitalLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle = pointStyle;
      // This setting also applies from ZoonLevel01 to ZoomLevel20, that means we can see city symbols the same stylewith ZoomLevel01 all the time.
      capitalLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
  
      // We need to add the capitalLayer to the LayerOverlay in the map.
      layers.Add(capitalLayer);
  }

Add TextStyle for City Name

TextStyles are used to label items on the map. As every ShapeFile has a relative .dbf file that includes descriptions for every record, the most common way to use TextStyles is for labeling. For example, the WorldCapitals Shapefile's corresponding .dbf file contains the field “CITY_NAME”. We can use this field to label the cities on our map.

ThinkGeo.Core has many TextStyles built in to help us quickly design attractive labels for the cities on our map. We can just pick the TextStyle we like and use it.

Now that we know how to render text and render symbols, let's define two different ZoomLevels in one single layer, and create our own custom Style and TextStyle.

  protected override void OnInitialized()
  {
      // We create a new Layer and pass the path to a ShapeFile into its constructor.
      ShapeFileFeatureLayer worldLayer = new ShapeFileFeatureLayer("./Data/countries/countries.shp");
      worldLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
  
      // Set the worldLayer to use a preset Style.
      AreaStyle areaStyle = new AreaStyle();
      areaStyle.FillBrush = new GeoSolidBrush(GeoColor.FromArgb(255, 233, 232, 214));
      areaStyle.OutlinePen = new GeoPen(GeoColor.FromArgb(255, 118, 138, 69), 1);
      areaStyle.OutlinePen.DashStyle = LineDashStyle.Solid;
      worldLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = areaStyle;
  
      // This setting will apply from ZoomLevel01 to ZoomLevel20, which means we can see the world the same style all the time no matter how far we zoom in or out.
      worldLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
  
      // We need to add the worldLayer to the LayerOverlay in the map.
      layers.Add(worldLayer);
  
      ShapeFileFeatureLayer capitalLayer = new ShapeFileFeatureLayer("./Data/capitals/WorldCapitals.shp");
      capitalLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
      PointStyle pointStyle = new PointStyle();
      pointStyle.SymbolType = PointSymbolType.Square;
      pointStyle.FillBrush = new GeoSolidBrush(GeoColors.White);
      pointStyle.OutlinePen = new GeoPen(GeoColors.Black, 1);
      pointStyle.SymbolSize = 6;
  
      PointStyle stackStyle = new PointStyle();
      stackStyle.SymbolType = PointSymbolType.Square;
      stackStyle.FillBrush = new GeoSolidBrush(GeoColors.Maroon);
      stackStyle.OutlinePen = new GeoPen(GeoColors.Transparent, 0);
      stackStyle.SymbolSize = 2;
  
      pointStyle.CustomPointStyles.Add(stackStyle);
      // We can customize our own Style. Here we passed in a color and a size.
      capitalLayer.ZoomLevelSet.ZoomLevel01.DefaultPointStyle = PointStyle.CreateSimpleCircleStyle(GeoColors.White, 7, GeoColors.Brown);
      // The Style we set here is available from ZoomLevel01 to ZoomLevel05. That means if we zoom in a bit more, theappearance we set here will not be visible anymore.
      capitalLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level05;
  
      capitalLayer.ZoomLevelSet.ZoomLevel06.DefaultPointStyle = pointStyle;
      // The Style we set here is available from ZoomLevel06 to ZoomLevel20. That means if we zoom out a bit more, th appearance we set here will not be visible any more.
      capitalLayer.ZoomLevelSet.ZoomLevel06.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
  
      // We need to add the capitalLayer to the LayerOverlay in the map.
      layers.Add(capitalLayer);
  
      // We create a new Layer for labeling the capitals.
      ShapeFileFeatureLayer capitalLabelLayer = new ShapeFileFeatureLayer("./Data/capitals/WorldCapitals.shp");
      capitalLabelLayer.FeatureSource.ProjectionConverter = new ProjectionConverter(4326, 3857);
      GeoFont font = new GeoFont("Arial", 9, DrawingFontStyles.Bold);
      GeoSolidBrush txtBrush = new GeoSolidBrush(GeoColors.Maroon);
      TextStyle textStyle = new TextStyle("CITY_NAME", font, txtBrush);
      textStyle.XOffsetInPixel = 0;
      textStyle.YOffsetInPixel = -6;
      // We use the preset TextStyle. Here we passed in the “CITY_NAME”, which is the name of the field we wanttolabelon map.
      capitalLabelLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle = TextStyle.CreateSimpleTextStyle("CITY_NAME", "Arial", 8, DrawingFontStyles.Italic, GeoColors.Black, 3, 3);
      // The TextStyle we set here is available from ZoomLevel01 to ZoomLevel05.
      capitalLabelLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level05;
  
      capitalLabelLayer.ZoomLevelSet.ZoomLevel06.DefaultTextStyle = textStyle;
      // The TextStyle we set here is available from ZoomLevel06 to ZoomLevel20.
      capitalLabelLayer.ZoomLevelSet.ZoomLevel06.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
  
      // We need to add the capitalLayer to the LayerOverlay in the map.
      layers.Add(capitalLabelLayer);
  }

Below is the result.

and the PointStyle will change as you zoom in.

This completes ​this scenario. The next thing you might want to do is to make it run on another machine ​that does not have a developer license. ​A runtime ​license is the one we are looking for. Here is the guide to generate a runtime license: http://wiki.thinkgeo.com/wiki/map_suite_runtime_license_guide_for_desktop

Summary

You now know the basics of using ThinkGeo Web for Blazor and are able to start adding this functionality into your own applications. Let's recap what we have learned about the object relationships and how the pieces of ThinkGeo work together:

  1. It is of the utmost importance that the unit of measurement (feet, meters, decimal degrees, etc.) be set properly for the map, based on the requirements of your data.
  2. ShapeFiles (and other data sources like Oracle, Postgre, SQL 2008, etc.) provide the data used by ThinkGeo to render a map.
  3. A Map is the basic class that contains all of the other objects that are used to define how the map will be rendered.
  4. A Map has one-to-many Layers. A Layer contains the data (from ShapeFile or other data sources) for drawing.
  5. A layer can have one-to-many ZoomLevels. ZoomLevels help to define ranges of when a layer should be shown or hidden.
thinkgeo_web_for_blazor_quick_start_guide.1569312105.txt.gz · Last modified: 2019/09/24 08:01 by johnnyz