Transaction Classes

Code Region 23-1: Using transactions

public void CreatingSketch(UIApplication uiApplication)
{
    Autodesk.Revit.DB.Document document = uiApplication.ActiveUIDocument.Document;
    Autodesk.Revit.ApplicationServices.Application application = uiApplication.Application;

    // Create a few geometry lines. These lines are transaction (not in the model),
    // therefore they do not need to be created inside a document transaction.
    XYZ Point1 = XYZ.Zero;
    XYZ Point2 = new XYZ(10, 0, 0);
    XYZ Point3 = new XYZ(10, 10, 0);
    XYZ Point4 = new XYZ(0, 10, 0);

    Line geomLine1 = Line.CreateBound(Point1, Point2);
    Line geomLine2 = Line.CreateBound(Point4, Point3);
    Line geomLine3 = Line.CreateBound(Point1, Point4);

    // This geometry plane is also transaction and does not need a transaction
    XYZ origin = XYZ.Zero;
    XYZ normal = new XYZ(0, 0, 1);
    Plane geomPlane = application.Create.NewPlane(normal, origin);

    // In order to a sketch plane with model curves in it, we need
    // to start a transaction because such operations modify the model.

    // All and any transaction should be enclosed in a 'using'
    // block or guarded within a try-catch-finally blocks
    // to guarantee that a transaction does not out-live its scope.
    using (Transaction transaction = new Transaction(document))
    {
        if (transaction.Start("Create model curves") == TransactionStatus.Started)
        {
            // Create a sketch plane in current document
            SketchPlane sketch = SketchPlane.Create(document,geomPlane);

            // Create a ModelLine elements using the geometry lines and sketch plane
            ModelLine line1 = document.Create.NewModelCurve(geomLine1, sketch) as ModelLine;
            ModelLine line2 = document.Create.NewModelCurve(geomLine2, sketch) as ModelLine;
            ModelLine line3 = document.Create.NewModelCurve(geomLine3, sketch) as ModelLine;

            // Ask the end user whether the changes are to be committed or not
            TaskDialog taskDialog = new TaskDialog("Revit");
            taskDialog.MainContent = "Click either [OK] to Commit, or [Cancel] to Roll back the transaction.";
            TaskDialogCommonButtons buttons = TaskDialogCommonButtons.Ok | TaskDialogCommonButtons.Cancel;
            taskDialog.CommonButtons = buttons;

            if (TaskDialogResult.Ok == taskDialog.Show())
            {
                // For many various reasons, a transaction may not be committed
                // if the changes made during the transaction do not result a valid model.
                // If committing a transaction fails or is canceled by the end user,
                // the resulting status would be RolledBack instead of Committed.
                if (TransactionStatus.Committed != transaction.Commit())
                {
                    TaskDialog.Show("Failure", "Transaction could not be committed");
                }
            }
            else
            {
                transaction.RollBack();
            }
        }
    }
}

Code Region 23-2: Combining multiple transactions into a TransactionGroup

public void CompoundOperation(Autodesk.Revit.DB.Document document)
{
    // All and any transaction group should be enclosed in a 'using' block or guarded within
    // a try-catch-finally blocks to guarantee that the group does not out-live its scope.
    using (TransactionGroup transGroup = new TransactionGroup(document, "Level and Grid"))
    {
        if (transGroup.Start() == TransactionStatus.Started)
        {
            // We are going to call two methods, each having its own local transaction.
            // For our compound operation to be considered successful, both the individual
            // transactions must succeed. If either one fails, we will roll our group back,
            // regardless of what transactions might have already been committed.

            if (CreateLevel(document, 25.0) && CreateGrid(document, new XYZ(0,0,0), new XYZ(10,0,0)))
            {
                // The process of assimilating will merge the two (or any number of) committed
                // transaction together and will assign the grid's name to the one resulting transaction,
                // which will become the only item from this compound operation appearing in the undo menu.
                transGroup.Assimilate();
            }
            else
            {
                // Since we could not successfully finish at least one of the individual
                // operation, we are going to roll the entire group back, which will
                // undo any transaction already committed while this group was open.
                transGroup.RollBack();
            }
        }
    }
}

public bool CreateLevel(Autodesk.Revit.DB.Document document, double elevation)
{
    // All and any transaction should be enclosed in a 'using'
    // block or guarded within a try-catch-finally blocks
    // to guarantee that a transaction does not out-live its scope.
    using (Transaction transaction = new Transaction(document, "Creating Level"))
    {
        // Must start a transaction to be able to modify a document
               
        if( TransactionStatus.Started == transaction.Start())
        {
            if (null != document.Create.NewLevel(elevation))
            {
                // For many various reasons, a transaction may not be committed
                // if the changes made during the transaction do not result a valid model.
                // If committing a transaction fails or is canceled by the end user,
                // the resulting status would be RolledBack instead of Committed.
                return (TransactionStatus.Committed == transaction.Commit());
            }

            // For we were unable to create the level, we will roll the transaction back
            // (although on this simplified case we know there weren't any other changes)

            transaction.RollBack();
        }
    }
    return false;
}

public bool CreateGrid(Autodesk.Revit.DB.Document document, XYZ p1, XYZ p2)
{
    // All and any transaction should be enclosed in a 'using'
    // block or guarded within a try-catch-finally blocks
    // to guarantee that a transaction does not out-live its scope.
    using (Transaction transaction = new Transaction(document, "Creating Grid"))
    {
        // Must start a transaction to be able to modify a document
        if (TransactionStatus.Started == transaction.Start())
        {
            // We create a line and use it as an argument to create a grid
            Line gridLine = Line.CreateBound(p1, p2);
                 
            if ((null != gridLine) && (null != document.Create.NewGrid(gridLine)))
            {
                if (TransactionStatus.Committed == transaction.Commit())
                {
                return true;
                }
            }

            // For we were unable to create the grid, we will roll the transaction back
            // (although on this simplified case we know there weren't any other changes)

            transaction.RollBack();
        }
    }
    return false;
}