.NET Cookbook 07: Building Dockable WPF PaletteSet Windows with Document-Locking Command Execution

1. Hosting Modern Dockable WPF MVVM Tool Palettes (`Gssoft.GstarCAD.Windows.PaletteSet`) & Cross-Document Locking

Modal WinForms dialogs block the engineer from panning, zooming, or picking geometry in the drawing viewport. Modern commercial GstarCAD .NET plugins utilize modeless, dockable `PaletteSet` containers hosting hardware-accelerated WPF UserControls (`ElementHost`). However, because a modeless WPF button click executes outside the context of a registered CAD command, mutating the active database directly throws an instant `eLockViolation` exception.

Critical Kernel & Memory Safety Rule: Whenever a user clicks a button or edits a DataGrid cell inside a modeless `PaletteSet`, your C# event handler **must** acquire an explicit document lock via `using (DocumentLock docLock = doc.LockDocument())` before starting a `Transaction`! Better yet, for operations that require interactive viewport prompts (`Editor.GetPoint`), dispatch a registered command string via `doc.SendStringToExecute("_MY_CMD ", true, false, false)`.

2. Managed C# .NET Implementation (GRX / .NET / LISP)

Reference GsMgd.dll and GsDbMgd.dll (with Copy Local = False) in your C# class library project to execute .NET Cookbook 07: Building Dockable WPF PaletteSet Windows with Document-Locking Command Execution inside the GstarCAD 2027 CLR runtime:

// GstarCAD 2027 C# .NET API — Dockable PaletteSet with Safe Document Locking
using System;
using Gssoft.GstarCAD.Runtime;
using Gssoft.GstarCAD.ApplicationServices;
using Gssoft.GstarCAD.Windows;

public class EnterprisePalette {
    private static PaletteSet _ps;
    [CommandMethod("GCAD_SHOW_PALETTE")]
    public void ShowPalette() {
        if (_ps == null) {
            _ps = new PaletteSet("GstarCAD PLM Explorer", new Guid("A1B2C3D4-E5F6-4789-9012-3456789ABCDE"));
            _ps.Style = PaletteSetStyles.ShowAutoHideButton | PaletteSetStyles.ShowCloseButton;
        }
        _ps.Visible = true;
    }
}

3. ObjectARX-to-GRX & .NET API Porting Matrix

When dual-targeting plugins for both AutoCAD and GstarCAD 2027 from a unified Git repository, reference the following symbol, header, and assembly mapping table:

4. Memory Management, Thread Safety & QA Checklist

• Deterministic Object Closure & Transaction Disposal: In C++ GRX, every acdbOpenObject() call that returns Acad::eOk must be paired with an explicit pObj->close() before starting a command or returning control to the editor. In C# .NET, always wrap StartTransaction() inside a using block and explicitly call tr.Commit().
• Document Locking from Modeless Contexts: Whenever modifying the active DWG database from a modeless WPF PaletteSet, WinForms dialog, or external COM event, acquire a write lock via doc.LockDocument() to prevent eLockViolation exceptions.
• Multi-Core Fiber & Main-Thread Discipline: The DWG database (`AcDbDatabase`) is not thread-safe for concurrent writes. Offload heavy geometric calculations or SQL/REST I/O to background worker threads, then marshal database mutations back to the main CAD UI thread.

Production Compilation, Packaging & Enterprise Deployment Guide

When deploying this developer recipe into commercial enterprise production, development leads should configure automated CI/CD build agents (GitHub Actions or Azure DevOps) using MSBuild command-line flags. Ensure that all dependent assemblies (such as GsMgd.dll and GsDbMgd.dll) have their reference property set to Copy Local = False (Private=False) to prevent deployment conflicts with the host GstarCAD 2027 application folder:

• Target Framework Alignment: For C# .NET plugins, target .NET Framework 4.8 or .NET 8.0 Windows Desktop runtime depending on your GstarCAD host version. For C++ GRX extensions, compile using Visual Studio 2022 (MSVC v143) with the platform toolset set to 64-bit (x64) and Character Set set to Unicode.
• Registry-Free Autoloading (.bundle): Package your compiled binary and menu CUIX files into an Autodesk/GstarCAD-compatible Application Package bundle folder (e.g., EnterprisePlugin.bundle/PackageContents.xml) and deploy directly to %APPDATA%\Autodesk\ApplicationPlugins or %PROGRAMDATA%\Gstarsoft\ApplicationPlugins for automatic silent loading without requiring administrative Windows registry rights.
• Automated Exception Trapping & Telemetry: Always wrap top-level command methods and event handlers inside structured try-catch or AutoLISP vl-catch-all-apply blocks to log diagnostic stack traces to corporate log repositories rather than letting unhandled exceptions crash the host drawing session.