WinForms Designer for VS Code

A Visual Studio–style WinForms form designer, running natively inside VS Code.

Open a form's Form1.cs and get a live, interactive preview of the rendered form — click controls, edit properties, drag and resize, wire events, and save minimal changes back into .Designer.cs. No round-trip through Visual Studio.

⚠️ Preview. This extension is under active development. It requires Windows and the .NET 9 SDK. See Status & limitations.

Property grid	Toolbox

Features

• Live form rendering from .Designer.cs — your controls (including custom/3rd-party ones) are really instantiated and painted, so the preview matches runtime.
• .NET Framework & DevExpress support (experimental) — forms whose controls target .NET Framework (net4x) render on a dedicated bundled .NET Framework 4.8 engine that instantiates the compiled controls, so classic component suites (e.g. DevExpress) look pixel-accurate. Each form is auto-routed to the right engine; the property grid, drag/resize/align, add/remove, z-order, cut/paste, tab-page add/rename/delete, dropping the project's own vendor controls from the toolbox, and the collection editors all apply live (the compiled preview is rebuilt on the running instance). A multi-target form the .NET 9 engine can't load can switch to the compiled preview with one click.
• VS Code–native workflow — opening Form.cs opens the designer; View Code switches back to text.
• Property grid — primitives, enums, complex types (Point, Size, Color, Font, Padding, Rectangle, Cursor), composite expansion, and standard-value dropdowns, plus VS-style Color, Font (expandable), flags-enum, Anchor/Dock, Cursor, and image editors. Component-reference properties (AcceptButton, ContextMenuStrip, ContainerControl, …) become a dropdown of compatible components (plus (this) for the form), and an ImageList-backed ImageIndex / ImageKey picks from a dropdown of indices / keys. Non-default values are bold, a description pane explains the selected property, and right-click Reset restores the default.
• Collection editors — the … button opens a VS-style Collection Editor for string collections (ComboBox / ListBox / CheckedListBox.Items), string-array properties (TextBox.Lines), ListView.Columns, DataGridView.Columns, and a recursive TreeView.Nodes tree editor (with per-node images, check state, tooltip, colors & font) — on both engines. A panel "Type Here" editor also reorders / adds / removes / renames MenuStrip / ToolStrip items.
• On-canvas menu & toolbar editing — edit MenuStrip / ToolStrip items directly on the strip: a "Type Here" slot to add (with a type picker), double-click / F2 to rename, click to select and Delete — including nested submenus, an off-tree ContextMenuStrip (from its tray chip), and the overflow area. Selecting an item opens its own property grid with an Events tab. On both engines.
• Images & .resx — render images from a form's sibling .resx, and import / clear Image / BackgroundImage / Icon back into both files.
• Layout panels — edit TableLayoutPanel cells & column/row styles, SplitContainer splitter distance, and FlowLayoutPanel order.
• Toolbox — ~39 System.Windows.Forms controls (with native icons) plus controls from your own project; Choose Toolbox Items and a control-source picker for custom / 3rd-party assemblies.
• Direct manipulation — select, move, resize (8 handles), keyboard nudge (arrow keys), multi-select + rubber-band, group move/delete, reparent, z-order, copy/paste, duplicate (Ctrl+D), lock controls, align / distribute / make-same-size, tab-order editor, snaplines, on-canvas smart-tags, and a right-click menu.
• Events — wire / unwire / rewire handlers, generate a stub, navigate to the handler body.
• Component tray and document outline for non-visual components and the control hierarchy.
• Localized UI (7 languages) — the designer surface, dialogs and messages can be shown in English, Русский, 简体中文, Français, Deutsch, Español or हिन्दी via the winformsDesigner.language setting.
• Safe save — targeted, byte-minimal text edits; everything outside the change is preserved exactly.

Requirements

• Windows (WinForms is Windows-only).
• .NET 9 SDK.
• .NET Framework projects (net4x, e.g. DevExpress) render through a bundled .NET Framework 4.8 engine — its runtime ships with Windows, so no extra install is needed.
• A trusted workspace (see below).

Getting started

1. Open a form's Form1.cs (with its generated Form1.Designer.cs sibling). The designer opens automatically.
2. Click a control to select it, then edit it in the Properties panel or drag/resize it directly.
3. Add controls from the Toolbox; press F4 to focus Properties.
4. Save to write minimal changes back into .Designer.cs.

Settings

Language

The designer surface, property grid, toolbox, dialogs and status/notification messages are localized and follow the winformsDesigner.language setting — chosen here, not from the VS Code display language. Changing it takes full effect after a Reload Window (you'll be prompted). Note: the VS Code command palette titles and the settings page itself follow VS Code's own Display Language (a platform limitation), so those pieces of "chrome" may stay in a different language than the designer UI.

Security & Workspace Trust

Rendering a designer loads and runs your project's control assemblies (constructors and OnPaint execute on preview), so the extension is disabled in untrusted workspaces. The engine interprets .Designer.cs through strict allowlists rather than executing arbitrary code from the file. Only open projects you trust.

Status & limitations

This is a preview. The core render → select → edit → save loop, property grid (with Color / Font / flags / Cursor / image editors, bold non-default values, description pane and reset), collection editors (Items / string-array Lines / ListView.Columns / DataGridView.Columns / TreeView.Nodes with per-node images / check / tooltip / colors / font, and a MenuStrip / ToolStrip "Type Here" reorder / add / remove / rename editor), on-canvas menu/toolbar item editing (add / rename / delete / select through nested / context-menu / overflow items, each with its own property grid and an Events tab), component-reference and ImageIndex / ImageKey property dropdowns, toolbox, layout-panel editing, .resx image support, 7-language UI localization, and safe save all work. .NET Framework (net48) hosting is an experimental compiled preview for net4x / DevExpress forms — render plus live property / drag / add / remove / z-order / cut / paste edits, tab-page add / rename / delete, collection editors, and dropping the project's own vendor controls from the toolbox. UITypeEditor modals and advanced .resx are still in progress. Please report issues — the WinForms: Export Designer Diagnostics command generates a ready-to-paste bug report.

Links

• Source, issues & contributing: https://github.com/SkivHisink/winforms-designer-vscode
• License: MIT