Find a specific graphic in GraphicsOverlay

FranciscoLopez

I have a GraphicsOverlay with n graphics and I want to find out a number of them with some attributes. Now I have the following code:

for (int i = 0; i < _graphicsOverlay.Graphics.Count(); i++)
{
int _index = Convert.ToInt32(_graphicsOverlay.Graphics[i].Attributes["ORDER"].ToString());
int _range = Convert.ToInt32(_graphicsOverlay.Graphics[i].Attributes["RANGE"].ToString());
string _type = _graphicsOverlay.Graphics[i].Attributes["TYPE"].ToString();
if (_index == mapUnits.Order && _range == range && _type== "RING")
{
_graphicsOverlay.Graphics.Remove(_graphicsOverlay.Graphics[i]);
return false;
}
}

So, my question is, Is there a better way to get a graphics group that meet certain criteria for certain attributes of the graph?

 

Thanks in advance.

JoeHershman

Not sure I understand the

return false;

inside the conditional, because it will only remove the first one it finds that meets this condition.

I would use LINQ to get a IEnumerable of the graphics I want to remove and then loop through it to do the removals.  Again not clear on the purpose of the return, but the below example would return false if anything needed to be removed

var graphics = _graphicsOverlay.Graphics.Where(g =>
	(int)g.Attributes["ORDER"] == mapUnits.Order && (int)g.Attributes["RANGE"] == range &&
	g.Attributes["TYPE"].ToString() == "RING");

bool result = true;

foreach (var graphic in graphics)
{
	_graphicsOverlay.Graphics.Remove(graphic);
	result = false;
}

return result;

  You are going to get an illegal cast exception if either ORDER or RANGE is null.  You could do something along these lines to avoid that possibility

var graphics = _graphicsOverlay.Graphics.Where(g =>
{
	int order = g.Attributes["ORDER"] == null ? 0 : (int)g.Attributes["ORDER"];
	int range = g.Attributes["RANGE"] == null ? 0 : (int)g.Attributes["RANGE"];
	string type = g.Attributes["TYPE"] == null ? string.Empty : g.Attributes["TYPE"].ToString();

	return order == mapUnits.Order && range == _range && type == "RING";
});

bool result = true;
foreach (var graphic in graphics)
{
	result = false;
	_graphicsOverlay.Graphics.Remove(graphic);
}

return result;