Showing/Hiding map content with Windows Phone maps API

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Croozeus - Sections

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croozeus 11:58, 19 November 2012 (EET)

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Article

Created: symbianyucca (08 Nov 2012)

Last edited: jasfox (25 Apr 2013)

Introduction

This article shows how to display/hide map content with Windows Phone maps API. The WP7 codes discussed here are implemented in examples made for WP7, and can be found from Maps Examples for Windows phone wiki page.

Implementation on WP7

With WP7 Bing maps API you could simply use the Visibility variable of the map object class for setting it visible or hidden as shown with following code snipped:

if (poly.Visibility == System.Windows.Visibility.Visible){
    poly.Visibility = System.Windows.Visibility.Collapsed;
}
else
{
    poly.Visibility = System.Windows.Visibility.Visible;
}

Implementation on WP8

With WP8 Maps API the above mentioned approach generally cannot be taken, only exception being the markers which with WP8 are actually just MapOverlay objects inside MapLayer. With them you could use the Visibility variable, provided that it is available for the actual object set as content for the MapOverlay.

Following example, the snippet below shows how this could be done with Ellipse objects used as content for MapOverlay.

if (markerLayer != null)
{
    for (var i = 0; i < markerLayer.Count(); i++)
    {
        Ellipse markker = (markerLayer[i].Content as Ellipse);
        if (markker != null)
        {
            if (markker.Visibility == System.Windows.Visibility.Visible)
            {
                markker.Visibility = System.Windows.Visibility.Collapsed;
            }
            else
            {
                markker.Visibility = System.Windows.Visibility.Visible;
            }
        }
    }
}

With polygon and polyline you would still have one option, and this would be to use the alpha channel defining the transparency factor for the color used with the map object. Note that with polygon, you do need to set the transparency for both line and the filling as shown in here:

if (poly.StrokeColor == Color.FromArgb(0xFF, 0x00, 0x00, 0xFF))
{
    poly.FillColor = Color.FromArgb(0x00, 0x00, 0xFF, 0x00);
    poly.StrokeColor = Color.FromArgb(0x00, 0x00, 0x00, 0xFF);
}
else
{
    poly.FillColor = Color.FromArgb(0x55, 0x00, 0xFF, 0x00);
    poly.StrokeColor = Color.FromArgb(0xFF, 0x00, 0x00, 0xFF);
}

Example code

The full example for this code can be found from Windows Phone 8 Maps examples project, the code used here is implemented for example in SimpleContent example inside that project.