How to highlight elements when selecting them

[desdinova]

List<ElementId> elemIdList = new List<ElementId>();
            try
            {
              
                while (true)
                {
                    elemIdList.Add((uidoc.Selection.PickObject(ObjectType.Element, "Pick a room").ElementId));
                    uidoc.Selection.SetElementIds(elemIdList);
                    uidoc.RefreshActiveView();
                   
                }
                
            }
            catch { }

hi friends

i want to highlight elements when i am selecting them like ctrl and pick objects

How can i do that in while loop in api?

Thanks in advance..... 

[Aaron.Lu]

Dear, what about shi:

    try
    {
        while (true)
        {
            elemIdList.Add((uidoc.Selection.PickObject(ObjectType.Element, "Pick a room").ElementId));
        }
    }
    catch 
    {
        uidoc.Selection.SetElementIds(elemIdList);
        uidoc.RefreshActiveView();
    }

[desdinova]

Thank you Aaron.Lu
It doesn't work for me.

[Aaron.Lu]

What is your revit version.
it works for me on Revit 2015.

[desdinova]

I use Revit 2015

[Aaron.Lu]

Not sure what is the problem...

Attachment is video to demo how it works,

Full code I'm using:

    [TransactionAttribute(TransactionMode.Manual)]
    public class Pickwhile : IExternalCommand
    {
        public Document doc;
        public Autodesk.Revit.ApplicationServices.Application RevitApp;
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            RevitApp = commandData.Application.Application;
            var uidoc = commandData.Application.ActiveUIDocument;
            if (uidoc == null)
            {
                message = "Please open a document";
                return Result.Failed;
            }

            doc = commandData.Application.ActiveUIDocument.Document;
            List<ElementId> elemIdList = new List<ElementId>();
            try
            {
                while (true)
                {
                    elemIdList.Add((uidoc.Selection.PickObject(ObjectType.Element, "Pick a room").ElementId));
                }
            }
            catch
            {
                uidoc.Selection.SetElementIds(elemIdList);
                uidoc.RefreshActiveView();

                var td = new TaskDialog("Info");
                td.MainInstruction = commandData.Application.ActiveUIDocument.Selection.GetElementIds().Aggregate("", (ss, el) => ss + "," + el).TrimStart(',');
                td.TitleAutoPrefix = false;
                td.Show();
            }

            return Result.Succeeded;
        }
    }

[desdinova]

Hi and thank you again...

I want to make selection like this..

Please see attachment.

Regards...

[Aaron.Lu · Accepted solution]

I think my demo code could do what you want.
if not, would you let me know what is the problem? e.g. errors or behaviors you not expected.

and another choice is to use PickObjects() method. Did you try that?

[desdinova]

Thank you again
PickObjects() method does what i want...