Obtain quantity sum of instances of type Revit API C#

[rita.aguiar]

Is it possible to obtain the quantity sum of all instances of a type through the Revit API?

Any help would be appretiated.

In similarity to what this schedule is obtaining:

[BenoitE&A]

I guess so : 

- you can filter your model the same way you do it in your Schedule (FilteredElementCollector, ofCategory, Where, etc...)

- you can evaluate the value of your given parameter for every Instance in this collector

- you can sum these.

[rita.aguiar]

@BenoitE&A 

Ah, what a pity. Is that the best way? I was hoping I could find a property that would return the sum so I didn't have to do it myself.

Thanks for the reply.

[BenoitE&A]

We gave it a thought with my associate and did not come with anything simpler. But frankly, it's not top-notch... really the same as creating a schedule...

[john_dalessandro · Accepted solution]

Because LINQ lazy loads, the following should only run through each element once and be pretty quick.

return new FilteredElementCollector(doc)
    .OfCategory(/* category */)
    .Sum(e => e.get_Parameter(/* parameter */).AsDouble());