Center Map on Collection

[Joe Bohen]

Hi,

 

I am using the radmap and placing  items onto the information layer using an example you provide. The items are an observable collection of the mapitem class:

 

Private items As New ObservableCollection(Of MapItem)()

 

This works well, but how would I get the best view for items created using this method where the items contain only the latitude and lonitude.

 

Regards,

Joe

 

 

<telerik:RadMap x:Name="radMap" DistanceUnit="Mile" ZoomLevel="6" DataContext="{Binding}" >

                            <telerik:InformationLayer Name="informationLayer">

                                <telerik:InformationLayer.ItemTemplate>

                                    <DataTemplate>

                                        <Border telerik:MapLayer.Location="{Binding Location}" x:Name="Border" ToolTip="{Binding DateofFix}"  DataContext="{Binding}">

                                            <telerik:MapLayer.HotSpot>

                                                <telerik:HotSpot X="0.5" Y="40" XUnits="Fraction" YUnits="InsetPixels" ElementName="path" />

                                            </telerik:MapLayer.HotSpot>

                                            <Grid>

                                                <Path x:Name="path" Stretch="None"

                              Stroke="{StaticResource MapPushpinStroke}"

                              StrokeThickness="4"

                              Data="M12,26.083 L16,26.083 13.916667,32.083 z M14,3 C20.075132,3 25,7.9248676 25,14 25,20.075132 20.075132,25 14,25 7.9248677,25 3,20.075132 3,14 3,7.9248676 7.9248677,3 14,3 z"

                              Fill="{Binding Background}">

                                                    <Path.Effect>

                                                        <telerik:IsFullTrust>

                                                            <![CDATA[

                                    <DropShadowEffect xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

                                        BlurRadius="7" ShadowDepth="1" />

                                    ]]>

                                                        </telerik:IsFullTrust>

                                                    </Path.Effect>

                                                </Path>

                                                <ContentPresenter Margin="0,40,0,0" Content="{Binding Content}" />

                                            </Grid>

                                        </Border>

                                    </DataTemplate>

                                </telerik:InformationLayer.ItemTemplate>

                            </telerik:InformationLayer>

                        </telerik:RadMap>

 

[Andrey]

Hi Joe,

You can use the code below for calculating the best view for items of this type.

If Me.items.Count > 0 Then
    Dim rect As LocationRect = Me.CalculateBestView(Me.items, New Size(2, 2))
    Me.radMap.SetView(rect)
End If

    Private Function CalculateBestView(itemsList As IEnumerable(Of MapItem), defaultSize As Size) As LocationRect
        Dim minLat As Double? = Nothing
        Dim maxLat As Double? = Nothing
        Dim minLong As Double? = Nothing
        Dim maxLong As Double? = Nothing
        Dim bestView As LocationRect
        For Each item As MapItem In itemsList
            Dim location = item.Location
            If minLat Is Nothing Then
                minLat = location.Latitude
            End If
            If maxLat Is Nothing Then
                maxLat = location.Latitude
            End If
            If minLong Is Nothing Then
                minLong = location.Longitude
            End If
            If maxLong Is Nothing Then
                maxLong = location.Longitude
            End If
            minLat = Math.Min(location.Latitude, minLat.Value)
            minLong = Math.Min(location.Longitude, minLong.Value)
            maxLat = Math.Max(location.Latitude, maxLat.Value)
            maxLong = Math.Max(location.Longitude, maxLong.Value)
        Next
        If minLat IsNot Nothing AndAlso minLong IsNot Nothing AndAlso maxLat IsNot Nothing AndAlso maxLong IsNot Nothing Then
            bestView = New LocationRect(New Location(minLat, minLong), New Location(maxLat, maxLong))
            If bestView.IsEmpty Then
                bestView = New LocationRect(New Location(bestView.North + defaultSize.Height / 2.0, bestView.West - defaultSize.Width / 2.0),
                       New Location(bestView.North - defaultSize.Height / 2.0, bestView.West + defaultSize.Width / 2.0))
            End If
            Return bestView
        Else
            Return New LocationRect
        End If
    End Function

Greetings,
Andrey Murzov
the Telerik team