Revit中创建IndependentTag遇问题：代码调用失败求助

Hey there, let's get your tag creation code working. The main issue right now is that your Execute method isn't implemented—it's just throwing a NotImplementedException, which means the command never actually runs any logic. Let's fix that, plus add the necessary transaction wrapping and proper wall selection.

Here's the corrected code with explanations:

using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using System;

[Transaction(TransactionMode.Manual)]
public class Tagtest : IExternalCommand
{
    public IndependentTag CreateIndependentTag(Document document, Wall wall)
    {
        TaskDialog.Show("Create Independent Tag Method", "Start Of Method Dialog");

        // Ensure active view is not a 3D view (tags don't work well in 3D)
        var view = document.ActiveView;
        if (view is View3D)
        {
            throw new InvalidOperationException("Tags cannot be created in 3D views. Please switch to a 2D view.");
        }

        // Define tag mode and orientation
        var tagMode = TagMode.TM_ADDBY_CATEGORY;
        var tagOrientation = TagOrientation.Horizontal;

        // Get wall's midpoint for tag placement
        var wallLoc = wall.Location as LocationCurve;
        if (wallLoc == null)
        {
            throw new InvalidOperationException("Selected wall does not have a curve location.");
        }
        var wallMid = wallLoc.Curve.Evaluate(0.5, true);
        var wallRef = new Reference(wall);

        // Create the tag inside the transaction
        var newTag = IndependentTag.Create(document, view.Id, wallRef, true, tagMode, tagOrientation, wallMid);
        if (newTag == null)
        {
            throw new Exception("Create IndependentTag Failed.");
        }

        // Note: Setting the wall type's "Type Mark" will change this value for ALL walls of this type
        // If you want per-tag custom text, use a tag family that uses an instance parameter instead
        var wallType = wall.WallType;
        var typeMarkParam = wallType.LookupParameter("Type Mark");
        if (typeMarkParam != null && typeMarkParam.IsReadOnly == false)
        {
            typeMarkParam.Set("Hello");
        }
        else
        {
            TaskDialog.Show("Warning", "Could not set Type Mark parameter for the wall type.");
        }

        // Configure leader settings
        newTag.LeaderEndCondition = LeaderEndCondition.Free;
        var elbowPnt = wallMid + new XYZ(5.0, 5.0, 0.0);
        newTag.LeaderElbow = elbowPnt;
        var headerPnt = wallMid + new XYZ(10.0, 10.0, 0.0);
        newTag.TagHeadPosition = headerPnt;

        TaskDialog.Show("Create Independent Tag Method", "End Of Method Dialog");
        return newTag;
    }

    public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
    {
        UIApplication uiApp = commandData.Application;
        UIDocument uiDoc = uiApp.ActiveUIDocument;
        Document doc = uiDoc.Document;

        try
        {
            // Prompt user to select a wall
            Reference pickedRef = uiDoc.Selection.PickObject(Autodesk.Revit.UI.Selection.ObjectType.Element, "Select a wall to tag");
            Element elem = doc.GetElement(pickedRef);
            Wall wall = elem as Wall;

            if (wall == null)
            {
                message = "Selected element is not a wall.";
                return Result.Failed;
            }

            // All modifications to Revit document must be inside a transaction
            using (Transaction trans = new Transaction(doc, "Create Independent Tag"))
            {
                trans.Start();
                CreateIndependentTag(doc, wall);
                trans.Commit();
            }

            return Result.Succeeded;
        }
        catch (Autodesk.Revit.Exceptions.OperationCanceledException)
        {
            // User canceled the selection
            return Result.Cancelled;
        }
        catch (Exception ex)
        {
            message = ex.Message;
            return Result.Failed;
        }
    }
}

Key Fixes & Improvements: #

• Implemented the Execute Method: This is the entry point for your external command. We now get the active document, prompt the user to select a wall, and wrap all model changes in a required transaction.
• Added Error Handling: Checks for invalid views, non-wall selections, missing parameters, and handles user cancellation gracefully.
• Clarified Type Mark Behavior: Setting the wall type's "Type Mark" affects all walls of that type. For per-tag unique text, use a tag family bound to an instance parameter instead of a type parameter.
• Proper Transaction Wrapping: All code modifying the Revit document (tag creation, parameter changes) is inside a transaction, which is mandatory for committing changes to the model.

Give this code a try—when you run the command, you'll be prompted to select a wall, and it should create the tag with the specified leader positions and "Hello" as the Type Mark.

内容的提问来源于stack exchange，提问作者Chris Hildebran