change textbox input language on change of app language

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C#

globalization

Metro-design

I am working on a metro app which provides a change language option to user, so that it changes the application language. I have used resource file for this and coded like this

<pre lang="c#">
    Windows.Globalization.ApplicationLanguages.PrimaryLanguageOverride = language.LanguageCode;

I also changed UI direction according to language Left-to-right or Right-to-left.
Now I want that when user enter some text from keyboard in textbox, it enters input in current application language not of system language.
How I manage this.