Fix a bug where the collections MapElements cannot be manipulated fro…

[ocalvo]

This change fixes an issue with WPF and WinForms MapElements property.
In WPF the property is initialized as null and in WinForms any change to the property is lost.

Issue: #

112[https://github.com//issues/112]
62[https://github.com//issues/62]

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

When adding items to the Map.MapElements collection they will not appear on the map, code works in UWP but not in WinForms.

private void Map_MapTapped(object sender, MapInputEventArgs e)
{
	var pushpin = new MapIcon
	{
		Location = e.Location,
		Title = "Here's something interesting!",
		CollisionBehaviorDesired = MapElementCollisionBehavior.RemainVisible,
		NormalizedAnchorPoint = new Point(0.5, 1)
	};

	Map.MapElements.Add(pushpin);

	Debug.WriteLine(Map.MapElements.Count);
}

Expected behavior
I would expect the map element to be added...

What is the new behavior?

After calling Map.MapElements.Add(pushpin), the element is added and it is shown on the Map control.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Pull Request has been submitted to the documentation repository instructions. Link:
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes

We are removing the metadata property MapElementsProperty in the WPF control as this is no longer required.

Other information

[Austin-Lamb]

Main thing I think should be done before merging this is getting the Layers property to work too, since that was reported as having the same bug.

[JuanPapas]

Regarding the removal of Dependency Properties, I assume that means data binding on those will be not possible. Am I missing something?

Synced offline.