Validation in Wisej.NET

Validation in Wisej.NETVideo lessons, auto-graded quizzes, real C# labs that run in the browser and a verifiable certificate — free on learnwisej.com.

Open the course

Seven runnable Wisej.NET 4 applications following the course specifications, lesson guides, lab steps and walkthroughs. Each module is a cumulative snapshot of ValidationClinic, with a contacts grid, a customer intake form, a per-session in-memory repository and a live server trace. The final module is the capstone.

The source of this sample

iceteagroup/LearnWisej-SamplesValidation in Wisej.NET Course

Browse this folder on GitHub

Or clone it: git clone https://github.com/iceteagroup/LearnWisej-Samples.git

The modules

Module	What it builds
1 · Validation Fundamentals	The customer intake form introduces Validating, Validated, e.Cancel, AutoValidate, a working Cancel button and the ValidateChildren() save guard.
2 · Programmatic Validation and ErrorProvider Feedback	The intake form adds pure FieldValidation results, one ErrorProvider, per-field clearing, a visible summary and an InvalidMessage comparison on the customer code.
3 · Built-in Rules and the Validation Extender	The Validation extender replaces the repeated field handlers with reusable Required, Email, Integer, Telephone, Currency and Regex rule arrays.
4 · Custom Validation Methods, Services and Rules	A UI-independent ContactValidator, a MinimumAgeValidationRule and paired start/end date feedback separate field shape from business meaning.
5 · Data-Bound Validation and Model Errors	The form binds to an annotated model, commits pending edits before validation and maps model errors to fields. A separate dialog demonstrates automatic IDataErrorInfo feedback and switching the provider source.
6 · DataGridView Cell Validation and Row Errors	The contacts grid rejects uncommitted bad email/age values, explains conversion failures, marks Closed rows without a date and checks every row before saving the working copy.
7 · Production Validation UX and Capstone	The capstone combines binding, field rules, annotations, business rules and the contacts grid in one ordered Save pipeline. SummaryErrorProvider keeps extender, icon and summary feedback together.

Run a module

Requirements: .NET 10 SDK, NuGet access to Wisej-4 4.1.0 and a Wisej development license or trial. Open a module's ValidationClinic.slnx in Visual Studio and press F5, or run:

cd "Validation in Wisej.NET Course/Module 7/ValidationClinic"
dotnet run -f net10.0 --urls http://localhost:5907

Each project targets net10.0-windows and net10.0. Ports 5901-5907 let the snapshots run side by side. The capstone tests run from Module 7 with dotnet test ValidationClinic.Tests/ValidationClinic.Tests.csproj. Nothing requires a database, a third-party service or a deployment.

Conventions

• Designer-style .Designer.cs files hold the named controls; short event handlers and helpers live in code-behind.
• Open customer intake to work through the form rules. Load valid/invalid values makes each path reproducible.
• The trace records validation stages; saved-contact and write counts distinguish editing from persistence.
• Cancel bypasses validation. EnableAllowFocusChange lets the user reach related fields; Save still stops.
• Module 5 adds a separate IDataErrorInfo comparison dialog. Module 6 adds Save grid; Module 7 saves the intake and grid together only after all stages pass. Cancel intake before correcting a grid row.
• Grid rows and form models are working copies. A failed validation or repository write never mutates the saved snapshot.
• The annotated nullable Age model accepts null by itself; the form's Required rule and the grid's integer rule supply the required-field policy. Non-UI callers must choose that policy and run validators explicitly.