Skip to main content

Silverlight 3 beta 1 and Virtual Earth part 2 (The Map)

In my previous post I covered getting GEO spatial data into SQL and creating a service Silverlight can use to get the data in a usable format. In this post we are going to talk about how to create a Silverlight application to overlay geo spatial data on the Virtual Earth map. First thing first. Download the Silverlight Virtual Earth map control. Once you have done that start a new Visual Studio 2008 Silverlight project and add a reference to the Microsoft.VirtualEarth.MapControl and copy the following code into the XAML of your default window or page.
<Grid x:Name="LayoutRoot" Background="White">
    <m:Map Name="MyMap" ZoomLevel="4" Center="39.36830,-95.27340" Grid.Row="1"/>
</Grid>

Make sure you add this namespace as well for the VE add-in

xmlns:m="clr-namespace:Microsoft.VirtualEarth.MapControl;assembly=Microsoft.VirtualEarth.MapControl"

That is all you have to do. If you run your application you should now have a VE map on it. Now lets get to the fun stuff. In your code behind for the page add a using statement to Microsoft.VirtualEarth.MapControl and add a service reference to the web service you created to provide the spatial data.  Here is what my initialization method looks like:

InitializeComponent();
 
SLSpatialTypesService.SpatialTypeServiceClient serviceClient = new GovSage.SLSpatialTypesService.SpatialTypeServiceClient();
serviceClient.GetCongDistsAsync();
serviceClient.GetCongDistsCompleted += new EventHandler<GovSage.SLSpatialTypesService.GetCongDistsCompletedEventArgs>
    (serviceClient_GetCongDistsCompleted);

As you can see all I am doing is instantiating my service and setting up an event callback for when the call completes. The real work happens when this call comes back.

   1: void serviceClient_GetCongDistsCompleted(object sender, GovSage.SLSpatialTypesService.GetCongDistsCompletedEventArgs e)
   2: {
   3:     foreach (KeyValuePair<string, ObservableCollection<string>> locations in e.Result)
   4:     {
   5:         MapPolyline polyline = new MapPolyline();
   6:         polyline.Stroke = new SolidColorBrush(Colors.White);
   7:         polyline.StrokeThickness = 1;
   8:         polyline.Opacity = 0.5;
   9:         polyline.Locations = new LocationCollection();
  10:         polyline.Name = locations.Key;
  11:         
  12:         foreach (string location in locations.Value)
  13:         {
  14:             string[] latlong = location.Split(new char[] {','});
  15:             Location thisLocation = new Location(Double.Parse(latlong[0]), Double.Parse(latlong[1]));
  16:            
  17:             polyline.Locations.Add(thisLocation);
  18:         }
  19:  
  20:         switch (MyMap.Children.Count)
  21:         {
  22:             case 1:
  23:                 polyline.Fill = new SolidColorBrush(Colors.Blue);
  24:                 break;
  25:             case 2:
  26:                 polyline.Fill = new SolidColorBrush(Colors.Green);
  27:                 break;
  28:             case 3:
  29:                 polyline.Fill = new SolidColorBrush(Colors.Purple);
  30:                 break;
  31:             case 4:
  32:                 polyline.Fill = new SolidColorBrush(Colors.Red);
  33:                 break;
  34:             case 5:
  35:                 polyline.Fill = new SolidColorBrush(Colors.Yellow);
  36:                 break;
  37:             case 6:
  38:                 polyline.Fill = new SolidColorBrush(Colors.Brown);
  39:                 break;
  40:             case 7:
  41:                 polyline.Fill = new SolidColorBrush(Colors.LightGray);
  42:                 break;
  43:             default:
  44:                 polyline.Fill = new SolidColorBrush(Colors.Cyan);
  45:                 break;
  46:         }
  47:         polyline.MouseEnter += new MouseEventHandler(polyline_MouseEnter);
  48:         polyline.MouseLeave += new MouseEventHandler(polyline_MouseLeave);
  49:         MyMap.Children.Add(polyline);
  50:     }
  51: }

I get a KeyValuePair back from the web service. To create all my overlays I loop through each key value I get back. My key is my area name and the second value is an ObservableCollection of type string. In the first few lines (5-10) all I am doing is creating a new MapPolyline for each item and setting its properties and instantiating its LocationCollection. Then for each item in my ObservableCollection I loop and create a new location in my polyline. All I have to do is split the string value on the “,” and create a new location based on the latitude and longitude I am return and add it to the location collection. In my case I create 7 different MapPolyline objects each having about a hundred locations attached to them. 

At this point I have created all the objects I need to overlay on my map. Once I leave the inner foreach statement I hit a case statement that simply looks at how many children my map has and sets the polyline fill color for that object to a certain color. This allows each overlay area to have a different color.

Down at line 47 I start the code to add each MapPolyline to my map. Once you have added each as a child you should now be able to load your map and see your overlays (just make sure the latitude and longitude items you added for your locations actually matches the area you are expecting. If not your MapPolylines may get added to a completely different area of the map).

My map now looks like this and as I move in and out my MapPolylines adjust as well.

 

image

If your map scrolling is not smooth you need to do more reducing (reducing was talked about in part 1).

Comments

Anonymous said…
This comment has been removed by a blog administrator.

Popular posts from this blog

Uniting Testing Expression Predicate with Moq

I recently was setting up a repository in a project with an interface on all repositories that took a predicate. As part of this I needed to mock out this call so I could unit test my code. The vast majority of samples out there for mocking an expression predicate just is It.IsAny<> which is not very helpful as it does not test anything other then verify it got a predicate. What if you actually want to test that you got a certain predicate though? It is actually pretty easy to do but not very straight forward. Here is what you do for the It.IsAny<> approach in case someone is looking for that. this .bindingRepository.Setup(c => c.Get(It.IsAny<Expression<Func<UserBinding, bool >>>())) .Returns( new List<UserBinding>() { defaultBinding }.AsQueryable()); This example just says to always return a collection of UserBindings that contain “defaultBinding” (which is an object I setup previously). Here is what it looks like when you want to pass in an exp

Password Management

The need to create, store and manage passwords is a huge responsibility in modern day life. So why is it that so many people do it so poorly? This is a loaded questions with answers ranging from people being uneducated, to lazy, to educated but not affective in their methods and many more. This blog is to help those (in some way even myself) around me strengthen their online security. Why does it matter? To answer this let's look at a few numbers. According to the US Department of Justice (DOJ)’s most recent study , 17.6 million people in the US experience some form of identity theft each year. Ok fine but that is identity theft that has nothing to do with password management. What is one way someone can start getting information about who you are? How do they get access to steal your money? From Cyber Security Ventures 2019 report : "Cybersecurity Ventures predicts that healthcare will suffer 2-3X more cyberattacks in 2019 than the average amount for other industries. W

Experience Profile Anonymous, Unknown and Known contacts

When you first get started with Sitecore's experience profile the reporting for contacts can cause a little confusion. There are 3 terms that are thrown around, 1) Anonymous 2) Unknown 3) Known. When you read the docs they can bleed into each other a little. First, have a read through the Sitecore tracking documentation to get a feel for what Sitecore is trying to do. There are a couple key things here to first understand: Unless you call " IdentifyAs() " for request the contact is always anonymous.  Tracking of anonymous contacts is off by default.  Even if you call "IdentifyAs()" if you don't set facet values for the contact (like first name and email) the contact will still show up in your experience profile as "unknown" (because it has no facet data to display).  Enabled Anonymous contacts Notice in the picture I have two contacts marked in a red box. Those are my "known" contacts that I called "IdentifyAs"

Anatomy of Sitecore Business Rule - Macros

In previous posts, we talked about  field syntax and the basic structure of business rules . This time we are going to dive into macros in the business rules. Macros are used as part of the business rule syntax. The syntax looks like this and calls for 4 parameters. [Property to set, Operator/Macro, AdditionalParameters, Display text]. When I first started working with business rules the difference between operator and macro was confusing. To add to this confusion some of the out-of-the-box macros are named with the term "operator" (like ListOperator who's configuration points to a class called ListMacro and the class implements IRuleMacro). Anything under the path /sitecore/system/Settings/Rules/Definitions/Macros should be a macro and should implement IRuleMacro. Macros have the follow characteristics: They inherit the IRuleMacro interface The interface requires this execute method void Execute(XElement element, string name, UrlString parameters, string value)

Excel XIRR and C#

I have spend that last couple days trying to figure out how to run and Excel XIRR function in a C# application. This process has been more painful that I thought it would have been when started. To save others (or myself the pain in the future if I have to do it again) I thought I would right a post about this (as post about XIRR in C# have been hard to come by). Lets start with the easy part first. In order to make this call you need to use the Microsoft.Office.Interop.Excel dll. When you use this dll take note of what version of the dll you are using. If you are using a version less then 12 (at the time of this writing 12 was the highest version) you will not have an XIRR function call. This does not mean you cannot still do XIRR though. As of version 12 (a.k.a Office 2007) the XIRR function is a built in function to Excel. Prior version need an add-in to use this function. Even if you have version 12 of the interop though it does not mean you will be able to use the function. The