DataGridView, Validation, and Performance

From WinForms to the WebModule 5The lesson guide, the walkthrough video, the knowledge check and the hands-on lab this sample was built from are on learnwisej.com — free, with an AI tutor in every lesson.

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The orders grid is ported over a production-sized store (200,000 orders) and made usable over a network with a default filter, server-side sort, virtual rows (50-row blocks on demand) and a Σ row computed on the server. Validation moves out of the form into OrderValidator, and the edit dialog shows its messages field by field through an ErrorProvider.

The source of this sample

iceteagroup/LearnWisej-SamplesFrom WinForms to the Web Course/Module 5

Browse this folder on GitHub

Or clone it: git clone https://github.com/iceteagroup/LearnWisej-Samples.git — then open OrderDesk.Web.slnx in Visual Studio and press F5.

Run it

cd "LearnWisej-Samples/From WinForms to the Web Course/Module 5/OrderDesk.Web"
dotnet run -f net10.0 --urls http://localhost:5605

Then open http://localhost:5605. (Visual Studio: open OrderDesk.slnx, F5.) The first session of the process seeds the 200,000-row store (about a second, ~60 MB); every later session finds it ready.

What to try

Action	What you should see
Page load	"OrderDesk — Orders": the Open orders, newest first (1042 Northwind Traders 4,820.00 Open on top), the Σ footer with the count and total of every Open order, and the Performance panel: Rows fetched 50 (virtual) out of ~80,000 matching
Scroll the grid	one more block fetch per new block of 50 rows; blocks already held are not fetched again
Type north in the search box → Apply	a new count + Σ on the server; only Northwind Traders orders remain, still 50 rows per block
Status All / sort Total ↓ → Apply	the query changes; the browser sorts nothing
Edit… (or double-click a row) → change the status → Save	the dialog closes, a toast "Order n saved.", the grid re-counts and shows the new value
New order → Save without filling anything	the ErrorProvider marks Customer and PO number, "Add at least one order line." arrives as a toast, and the dialog stays open

Where things live

Module 5/
└─ OrderDesk.Web/                   the Wisej.NET 4 app (net10.0-windows;net10.0)
   ├─ Program.cs / Startup.cs       session entry point (Application.MainPage) / Kestrel host (app.UseWisej())
   ├─ Domain/                       Module 1 business logic unchanged, plus:
   │  ├─ Services/OrderQuery.cs     OrderQuery (filter · sort · page), PagedResult<T>, OrderSummary
   │  ├─ Services/OrderStore.cs     OrderStore.Large (200,000 orders, seeded once), LargeOrderRepository, OrderQueryService
   │  └─ Services/OrderValidator.cs OrderValidator → ValidationResult (field-level)
   ├─ Dialogs/EditOrderDialog.cs    the ported edit dialog: ErrorProvider + server-side validator
   ├─ Views/Ui.cs                   toast helper
   ├─ MainPage.cs / .Designer.cs    the orders grid, the Σ footer and the Performance panel
   └─ docs/                         the lab deliverables

Runtime facts

• DataGridView.VirtualMode + RowCount + CellValueNeeded behave as in WinForms; a Dictionary keyed by block start is all the caching the page needs. Column sorting is off (SortMode = NotSortable) because the grid holds a page.
• Form.ShowDialog() does not block in Wisej.NET: the edit dialog is shown with ShowDialog((form, result) => …) and disposed in the callback.
• The edit dialog edits one order line (the first); saving an order that had several lines replaces them with that line. The store is per process, so the change lasts until the app restarts.
• The payload figure is an estimate (cell text + ~96 bytes of framing per row); DevTools → Network → WS frames has the exact figure.
• The projects multi-target net10.0-windows;net10.0, so dotnet run needs -f net10.0 (or -f net10.0-windows).