DataGridView Mastery

Mastering the Control LibraryModule 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.

Open the course

This example is the DataGridView section is the Orders grid —

• ordersGrid + an ordersSource BindingSource, AutoGenerateColumns = false and six explicit columns;
• a status cell with AllowHtml whose badge is built in ordersGrid_CellFormatting with WebUtility.HtmlEncode;
• a custom editor (MonthCalendar on colDueDate.Editor, moved by CellBeginEdit / CellEndEdit) and a command column (colOpen) that calls OrderService.GetOrder(id);
• a virtual-mode path: RowCount from the service, CellValueNeeded served by OrderCache, pages prefetched in DataRead;
• a filter strip docked Top and a status strip docked Bottom, layered with SendToBack / BringToFront.

This module fills Sections/DataGridViewPage and adds Orders/, two models, two services and docs/GridDecisions.md.

The source of this sample

iceteagroup/LearnWisej-SamplesMastering the Control Library Course/Module 5

Browse this folder on GitHub

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

Run it

cd "LearnWisej-Samples/Mastering the Control Library Course/Module 5/OperationsConsole"
dotnet run -f net10.0 --urls http://localhost:5705

Then open http://localhost:5705 and select DataGridView.

What to try

Action	What you should see
Open DataGridView	the first 250 of 4,000 orders with status badges; amber status suggests narrowing the filter or Virtual mode
Type Contoso, Apply	the loader for a moment, then the matching orders and a green status
Pick a status, Apply	the same, filtered
Type zzzz, Apply	the grid's "No orders match this filter." card, amber status
Click a row	status strip Selected: SO-100123, StatusBar Record: SO-100123
Click Open in a row	an info Toast and the whole order on the status line
Double-click a due date, pick a later day, leave the cell	green status and Toast; the cell shows the new date
…pick a day in the past	red status "A due date in the past cannot be saved …"; the cell keeps the stored date
Tick Virtual mode	Rows: 4,000; scroll and the page-fetch count grows by one per 200-row block
Tick Simulate service failure, Apply	red status and an error Toast; the rows on screen stay. Untick and Apply again to recover
Refresh on the ToolBar	re-runs the current filter on the current path

Where things live

OperationsConsole/
├─ Sections/DataGridViewPage.cs / .Designer.cs   grid, strips, cell handlers
├─ Orders/OrderFilter.cs, OrderColumns.cs, OrderUpdateResult.cs
├─ Models/OrderRow.cs, OrderPage.cs
├─ Services/OrderService.cs      4,000 generated orders, GetOrders / Count / GetPage / GetOrder / UpdateDueDate, SimulateFailure
├─ Services/OrderCache.cs        the page cache behind CellValueNeeded (200-row pages, 4 pages, never throws)
└─ docs/GridDecisions.md         column, editor, large-data and composition decisions

Known simplifications

• 4,000 generated orders instead of the 200,000 — enough to show page fetches and eviction.
• The bound path is capped at 250 rows on purpose.
• The due-date column is read-only on the virtual path (the cache is a read model).
• Wisej.NET 4.1 has no CellContentClick; the command column is wired to CellClick and keeps the handler name.