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.
- 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), composite expansion, and standard-value dropdowns.
- Toolbox — ~39
System.Windows.Forms controls plus controls from your own project assembly.
- Direct manipulation — select, move, resize (8 handles), multi-select + rubber-band, group move/delete, align toolbar, tab-order editor, snaplines.
- 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.
- Safe save — targeted, byte-minimal text edits; everything outside the change is preserved exactly.
Requirements
- Windows (WinForms is Windows-only).
- .NET 9 SDK.
- A trusted workspace (see below).
Getting started
- Open a form's
Form1.cs (with its generated Form1.Designer.cs sibling). The designer opens automatically.
- Click a control to select it, then edit it in the Properties panel or drag/resize it directly.
- Add controls from the Toolbox; press F4 to focus Properties.
- Save to write minimal changes back into
.Designer.cs.
Settings
| Setting |
Default |
Description |
winformsDesigner.autoOpenDesigner |
true |
Open the designer automatically when a form's .cs becomes active. |
winformsDesigner.assemblyPath |
"" |
Explicit path to the built control assembly. Leave empty for auto-discovery. |
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 works; layout-parity polish, UITypeEditor modals, .NET Framework hosting, and advanced .resx are still in progress. Please report issues — the WinForms: Export Designer Diagnostics command generates a ready-to-paste bug report.
Links
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