Finding all elements of a given ElementType

[abe.buckingham]

I'm trying to gather all the Elements of a particular ElementType based on the type given. So for example If I'm given the WallType type in a generic class and I want the method to return a FilteredElementCollection of all the Wall objects in the document. Any idea how I might do this?

[Ning Zhou]

something like below, not tested, let me know if not working.

ElementClassFilter filter = new ElementClassFilter(typeof(Wall));
FilteredElementCollector collector = new FilteredElementCollector(doc);
collector.WherePasses(filter);
var query = from element in collector
where (element as Wall).WallType == myWallType
select element;
List<Wall> myWalls = query.Cast<Wall>().ToList<Wall>();

[abe.buckingham]

Your suggestion won't work because I do not know the elements I'm looking for apriori. The trouble is in this line.

ElementClassFilter filter = new ElementClassFilter(typeof(Wall));

I don't know that it's of type Wall, I only have the WallType type (not an instances of it).

[Ning Zhou]

check for all cases like below, don't know if there's better method?

// suppose et is ElementType
WallType wt = et as WallType;
if (wt != null) {
ElementClassFilter filter = new ElementClassFilter(typeof(Wall));
FilteredElementCollector collector = new FilteredElementCollector(doc);
collector.WherePasses(filter);
var query = from element in collector
where (element as Wall).WallType == myWallType
select element;
List<Wall> myWalls = query.Cast<Wall>().ToList<Wall>();
}
else {
FloorType ft = et as FloorType;
if (ft != null) {
...
}
}

[abe.buckingham]

check for all cases like below, don't know if there's better method?

This is exactly what I'm trying to avoid. I'd rather make the code modular so that in the future if additional ElementTypes are added to the API I don't have to update my code.

[abe.buckingham]

Ok I managed to get the functionality I wanted by using Categories. I took the first WallType in an iterator, then requested it's CategoryId and then use a WhereNotElementType and OfCategory methods on the filter to find the appropriate elements in the model.