// 创建几何线，无需在事务中
    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);

    // 几何平面无需开启事务
    XYZ origin = XYZ.Zero;
    XYZ normal = new XYZ(0, 0, 1);
    Plane geomPlane = Plane.CreateByNormalAndOrigin(normal, origin);

    // 为了在草图平面绘制模型线，需要开启事务

    // 所有的事务都应该包含在 'using' 块中
    // 或者在 try-catch-finally 块中进行保护
    // 以保证事务不会超出其作用域。
    using (Transaction transaction = new Transaction(doc))
    {
        if (transaction.Start("创建模型线") == TransactionStatus.Started)
        {
            // 在当前文档中创建草图平面
            SketchPlane sketch = SketchPlane.Create(doc,geomPlane);

            // 使用几何线和草图平面创建模型线
            ModelLine line1 = doc.Create.NewModelCurve(geomLine1, sketch) as ModelLine;
            ModelLine line2 = doc.Create.NewModelCurve(geomLine2, sketch) as ModelLine;
            ModelLine line3 = doc.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 = "点击 [确定] 提交，或 [取消] 回滚事务。";
            TaskDialogCommonButtons buttons = TaskDialogCommonButtons.Ok | TaskDialogCommonButtons.Cancel;
            taskDialog.CommonButtons = buttons;

            if (TaskDialogResult.Ok == taskDialog.Show())
            {
            // 由于多种原因，如果事务期间所做的更改未导致有效模型，则事务可能无法提交。
            // 如果提交事务失败或被最终用户取消，结果状态将是 RolledBack 而不是 Committed。
            // 创建一些几何线。不需要在文档事务中创建。
            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);

            // 这个几何平面也是事务性的，不需要事务
            XYZ origin = XYZ.Zero;
            XYZ normal = new XYZ(0, 0, 1);
            Plane geomPlane = Plane.CreateByNormalAndOrigin(normal, origin);

            // 为了在草图平面绘制模型线，需要开启事务

            // 所有的事务都应该包含在 'using' 块中
            // 或者在 try-catch-finally 块中进行保护
            // 以保证事务不会超出其作用域。
            using (Transaction transaction = new Transaction(doc))
            {
                if (transaction.Start("创建模型线") == TransactionStatus.Started)
                {
                    // 在当前文档中创建草图平面
                    SketchPlane sketch = SketchPlane.Create(doc, geomPlane);

                    // 使用几何线和草图平面创建 ModelLine 元素
                    ModelLine line1 = doc.Create.NewModelCurve(geomLine1, sketch) as ModelLine;
                    ModelLine line2 = doc.Create.NewModelCurve(geomLine2, sketch) as ModelLine;
                    ModelLine line3 = doc.Create.NewModelCurve(geomLine3, sketch) as ModelLine;

                    // 询问最终用户是否要提交更改
                    TaskDialog taskDialog = new TaskDialog("Revit");
                    taskDialog.MainContent = "点击 [确定] 提交，或 [取消] 回滚事务。";
                    TaskDialogCommonButtons buttons = TaskDialogCommonButtons.Ok | TaskDialogCommonButtons.Cancel;
                    taskDialog.CommonButtons = buttons;

                    if (TaskDialogResult.Ok == taskDialog.Show())
                    {
                        // 由于多种原因，如果事务期间所做的更改未导致有效模型，则事务可能无法提交。
                        // 如果提交事务失败或被最终用户取消，结果状态将是 RolledBack 而不是 Committed。
                        if (TransactionStatus.Committed != transaction.Commit())
                        {
                            TaskDialog.Show("失败", "事务无法提交");
                        }
                    }
                    else
                    {
                        transaction.RollBack();
                    }
                }
            }

            return "完成";
                if (TransactionStatus.Committed != transaction.Commit())
                {
                    TaskDialog.Show("失败", "事务无法提交");
                }
            }
            else
            {
                transaction.RollBack();
            }
        }
    }
    
    return "完成";