Switching the Language at Runtime

Localization in Wisej.NETModule 4The samples are ready before the course is: the module outline is on learnwisej.com, and the lessons, the knowledge checks and the hands-on labs follow when it launches — free, with an AI tutor in every lesson.

See the outline

culture: auto in Default.json, a language picker whose handler does nothing but assign Application.CurrentCulture, and an Application.CultureChanged handler that refreshes the resource-backed captions, reformats the culture-sensitive values and rebuilds the designer-localized editor - so every route into a culture change gets the same refresh. This folder is the complete application at this point in the course, with its own solution and port.

The source of this sample

iceteagroup/LearnWisej-SamplesLocalization in Wisej.NET Course/Module 4

Browse this folder on GitHub

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

Run it

cd "Localization in Wisej.NET Course/Module 4/GlobalDesk"
dotnet run -f net10.0 --urls http://localhost:6104

Open http://localhost:6104.

What to try

Action	Expected result
Pick de-DE	Everything changes at once - captions, values, and the editor, which the CultureChanged handler rebuilt for you. No second button press.
Pick de-AT	German text, Austrian numbers: 12 500 not 12.500, and € 1.850,75 not 1.850,75 €. There is no Strings.de-AT.resx; the text fell back to de.
Read the culture row	de-AT - Deutsch (Österreich) (Greift zurück auf de). The fallback is on screen instead of being a mystery.
Open http://localhost:6104/?lang=de-AT	The session starts in Austrian German and the picker is already on de-AT - its handler never ran.
Open the app in a second browser and switch the language in one	Nothing moves in the other. That is the test for a static culture field.

Notes for anyone extending the switch

• The picker assigns the culture and stops. Everything else is behind CultureChanged, so the URL parameter, a saved preference and a support tool all get the same refresh. Refreshing inline works from exactly one button.
• Unsubscribe in Dispose. Application.CultureChanged outlives the page; a page that forgets is kept alive by it for the rest of the session. This sample does it in the designer's Dispose, beside the components.
• SyncCultureCombo needs a re-entry flag, because assigning SelectedItem raises SelectedIndexChanged again. It also adds an unlisted culture rather than leaving the combo blank - a French browser is not an error.
• Never copy the culture into a static field. It is per session, and a static one means one user's click changes another user's screen. It never reproduces with one developer and one browser.
• Keep a language-region culture with no resource file of its own in the picker. de-AT makes fallback visible, and visible fallback is the only kind you can reason about.