WPF and Virtual Eath, Part 2

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Following on from here, I thought I’d add a little bit of pushpin support to my basic Virtual Earth control for WPF.

Essentially, I added a new property to the control called PushPins and each one of those is just a tuple of;

{ Latitude, Longitude, Text }

to be placed on the map.

This means that from XAML I can create a set of pushpins in a declarative way as in;

      <ve:VirtualEarth
        x:Name="veControl"
        Grid.Column="1"
        ZoomLevel="{Binding Path=Value, ElementName=slidey}"
        Latitude="{Binding Path=Text, ElementName=txtLat}"
        Longitude="{Binding Path=Text, ElementName=txtLon}"
        MapStyle="{Binding Path=Text, ElementName=cmbMapStyle}">
        <ve:VirtualEarth.PushPins>
          <ve:PushPin
            Latitude="47.6"
            Longitude="-122.33"
            Text="Seattle 1" />
          <ve:PushPin
            Latitude="47.7"
            Longitude="-122.33"
            Text="Seattle 2" />
          <ve:PushPin
            Latitude="47.8"
            Longitude="-122.33"
            Text="Seattle 3" />
        </ve:VirtualEarth.PushPins>

      </ve:VirtualEarth>

or I could databind them but either way in code if I want to manipulate that collection I can just do something like;

veControl.PushPins.Remove(p);

or;

   PushPin p = new PushPin()
        {
          Latitude = double.Parse(txtAddLat.Text),
          Longitude = double.Parse(txtAddLon.Text),
          Text = txtAddName.Text
        };
        veControl.PushPins.Add(p);

and that seems to work reasonably well. I also added a lookup routine which will asynchronously go and look up a postcode and bring it back as a Lat/Lon which means I can now write code such as;

veControl.BeginLookupPostCode(txtPostcode.Text, Callback, txtPostcode.Text);

and I’ll get a callback;

   void Callback(IAsyncResult result)
    {
      try
      {
        PostCodeLookupResult postCode = veControl.EndLookupPostCode(result);

        txtAddLat.Text = postCode.Latitude.ToString();
        txtAddLon.Text = postCode.Longitude.ToString();
      }
      catch (Exception e)
      {
        MessageBox.Show(e.Message);
      }
    }

which contains the Lat/Lon of the post-code that I looked up. What I haven’t done is to implement INotifyPropertyChanged on a PushPin and then move the pin on the map if you change a property – I’d currently have to remove and re-add any pushpin that changed.

I added some support for PushPins into my little test harness which now looks like;

image

and allows me to basically manipulate the new functionality.

Once again, I’ve put the code up here for download.