C# How to select bar of Rebar

[huynguyen96str]

Hi everyone! How to select bar of Rebar using C#.

Thank a lot.

[Mohamed_Arshad]

Hi @huynguyen96str 

   Welcome to Revit API Forum Community, I think you're new to Revit API Programming, So kindly check the below link which help you in understanding the basics of Revit API Programming and general procedure.

Revit API for Beginners.

https://thebuildingcoder.typepad.com/blog/2022/02/getting-started-once-again.html 

https://www.autodesk.com/support/technical/article/caas/tsarticles/ts/7I2bC1zUr4VjJ3U31uM66K.html 

You will get an Idea after seeing this, Then I have added a code snippet for Rebar Selection. You can Implement snippet and check the results.

Rebar Selection Code Snippet

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

#region Revit API Namesapce

using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.UI.Selection;
using Autodesk.Revit.DB.Structure;

#endregion

namespace RebarSelection 
{
    [Transaction(TransactionMode.Manual)]
    public class RebarSelection : IExternalCommand
    {
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {

            UIDocument uiDoc = commandData.Application.ActiveUIDocument;
            Document doc = uiDoc.Document;

            try
            {
                ///Rebar Selection
                ///Use ObjectType.Element for Complete rebar set Selection
                ///Use ObjectType.SubElement for single Rebar selection
                Reference selRef = uiDoc.Selection.PickObject(ObjectType.Subelement, new SelectionHelper(), "Select Rebar");

                if (selRef != null)
                {

                }

                return Result.Succeeded;

            }
            catch (Exception ex)
            {
                return Result.Cancelled;
            }
        }
    }

    public class SelectionHelper : ISelectionFilter
    {
        public bool AllowElement(Element elem)
        {
            if (elem is Rebar)
            {
                return true;
            }

            return false;
        }

        public bool AllowReference(Reference reference, XYZ position)
        {
            return true;
        }
    }
}

Hope this will Helps 🙂

[huynguyen96str]

Thank you very much!

You misunderstood my point.I don't want the user to pick the bar object in the rebar; instead, I want to use code to select that object.

[Mohamed_Arshad]

Hi @huynguyen96str 

   You have to use FilteredElementCollector. Kindly check the below code snippet for additional reference 

public void FilterRebarAndSetSelection(UIDocument uidoc)
{
    // Get the Revit Document
    Document doc = uidoc.Document;

    // Create a FilteredElementCollector to collect all Rebar elements
    FilteredElementCollector collector = new FilteredElementCollector(doc);
    
    // Filter only Rebar elements
    ICollection<Element> rebarElements = collector
        .OfClass(typeof(Rebar))
        .ToElements();

    // Convert the rebar elements to a list of ElementIds
    List<ElementId> rebarElementIds = rebarElements.Select(e => e.Id).ToList();

    // Set the current selection to the Rebar elements
    uidoc.Selection.SetElementIds(rebarElementIds);
}

call the method inside the Execute Function.

Hope this will helps 🙂