How to apply a selection filter on a ObjectIDCollection?
Hi,
By my side, i think Linq provides many useful extension methods to deal with all types of collection, those which do not implement IEnumerable<T> as ObjectIdcollection may be converted to IEnumerable<ObjectId> with Cast<ObjectId>>().
Look at the Linq extension methods here:
http://msdn.microsoft.com/en-us/library/9eekhta0.aspx
To filter a collection the Where extension methode is quite easy to use passing it a function (delegate) returning true for the elements you want to keep in the collection.
Example filtering the Line entities in an ObjectIdCollection (called ids):
ids.cast<ObectId>()
.Where(id => id.ObjectClass.DxfName == "LINE")
Accepted solution
It was just an example, for xdata, layer, you'll need to Open the objects. This can be done mapping the ObjectIdCollection to Entities with the Select() method, then adapting the Where() argument function as you need.
another example to be used within a Transaction (tr):
ids.Cast<ObjectId>()
.Select(id => (Entity)tr.GetObject(id, OpenMode.ForRead))
.Where(ent => ent.Layer == layerName)
Accepted solution
Hi,
Another way is to use the Editor.SelectionAdded event. You can call the Editor.SelectAll() method from a Transaction and combinate classical SelectionFilter with SelectionAdded event filtering.
Here's a little example (I 'm more comfortable giving example than trying to explain in English) where entities are classicaly filtered with layer and registered application and a SelectionAdded event handler is used to filter on the first xdata value: (1001, 'foo")
[CommandMethod("Test", CommandFlags.Modal)]
public void Test()
{
Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
try
{
SelectionFilter filter =
new SelectionFilter(new TypedValue[] { new TypedValue(8, "Layer1"), new TypedValue(1001, "RegApp") });
ed.SelectionAdded += OnSelectionAdded;
PromptSelectionResult psr = ed.SelectAll(filter);
if (psr.Status != PromptStatus.OK)
return;
ed.WriteMessage("\n{0} entities selected", psr.Value.Count);
}
finally
{
ed.SelectionAdded -= OnSelectionAdded;
}
}
void OnSelectionAdded(object sender, SelectionAddedEventArgs e)
{
ObjectId[] ids = e.AddedObjects.GetObjectIds();
for (int i = 0; i < ids.Length; i++)
{
using (Entity ent = (Entity)ids[i].Open(OpenMode.ForRead))
{
ResultBuffer xdata = ent.GetXDataForApplication("RegApp");
TypedValue[] tvs = xdata.AsArray();
if (tvs[0].TypeCode != 1000 || tvs[0].Value != "foo")
{
e.Remove(i);
}
}
}
}