Change LocalizedString at runtime

[AndyCaignie]

Hello,
I'm trying to make my app multi language using the LocalizedString.
However I have one major issue: some texts change at runtime. In the tutorial the Version {0} is used, but the formatted string is a constant. I need this to be filled in at runtime, as it displays a value that is retrieved after creation of the LocalizedString.
How can I change the text of the LocalizedString after it is created?

Thx in advance,
Andy

[maxkoshevoi]

Hi, this video and sample repo might be of some assistance:

• https://www.youtube.com/watch?v=wyKKa09z9VQ
• https://github.com/maxkoshevoi/XCTLocalizationDemo

[maxkoshevoi]

my issue is that the text of a label, button, .. changes at runtime

This is not an issue at all! LocalizedString was designed exactly for this purpose. Notice, that when you create LocalizedString, you supply a function to it:

public LocalizedString OpenMessage { get; } = new(() => string.Format(Translations.OpenMessages, nbrOfOpenMessages));

When you change the language, it reruns that function and updates it's value. The only thing that is required from your side is to change the language using LocalizationResourceManager (this will trigger an even that all LocalizedStrings are subscribed to).

Also note that changing the language through LocalizationResourceManager doesn't automatically change it for your resources (Translations), so you also need to write something like this: https://github.com/maxkoshevoi/XCTLocalizationDemo/blob/main/XCTLocalizationDemo/XCTLocalizationDemo/App.xaml.cs#L13

LocalizationResourceManager.Current.PropertyChanged += (_, _) => Translations.Culture = LocalizationResourceManager.Current.CurrentCulture;

Or in your repo: what if AppInfo.VersionString would change at runtime?

In the provided demo project displayed value of AppInfo.VersionString would be automatically changed at runtime via mechanisms described above.

[AndyCaignie]

Hello Maksym, thx for the clarification but I cannot get this working :-(. If I change the language then the function is indeed rerun, but not if nbrOfOpenMessages changes. I changed the string.format to a function but that didn't change the behaviour.

[maxkoshevoi]

Could you share a repro project?

[maxkoshevoi]

Issue in your case that language isn't changed. You change parts of the resulting string, and LocalizedString doesn't know about it, so it cannot re-render itself. You need to call OnPropertyChanged(nameof(CounterText)) after Counter is updated to notify view that LocalizedString needs to be re-rendered.
I've created two PRs in your repo to demonstrate possible fixes.
(AndyCaignie/TranslationProblem#1 AndyCaignie/TranslationProblem#2)

[AndyCaignie]

Hello Maksym thank you very much for your help, this works perfectly!

[AndyCaignie]

I created a small XAMARIN project on git: https://github.com/AndyCaignie/TranslationProblem
The about page is changed with 2 labels, when I push the button to add to the counter I would like both labels to update instead of just the second one