abp/framework/src/Volo.Abp.Localization/Volo/Abp/Localization/LanguageInfo.cs

using System;
using System.Globalization;
using JetBrains.Annotations;

namespace Volo.Abp.Localization;

[Serializable]
public class LanguageInfo : ILanguageInfo
{
    [NotNull]
    public virtual string CultureName { get; protected set; }

    [NotNull]
    public virtual string UiCultureName { get; protected set; }

    [NotNull]
    public virtual string DisplayName { get; protected set; }

    [NotNull]
    public virtual string TwoLetterISOLanguageName { get; protected set; }

    [CanBeNull]
    public virtual string FlagIcon { get; set; }

    
    protected LanguageInfo()
    {

    }

    public LanguageInfo(
        string cultureName,
        string uiCultureName = null,
        string displayName = null,
        string flagIcon = null)
    {
        ChangeCultureInternal(cultureName, uiCultureName, displayName);
        FlagIcon = flagIcon;
    }

    public virtual void ChangeCulture(string cultureName, string uiCultureName = null, string displayName = null)
    {
        ChangeCultureInternal(cultureName, uiCultureName, displayName);
    }

    private void ChangeCultureInternal(string cultureName, string uiCultureName, string displayName)
    {
        CultureName = Check.NotNullOrWhiteSpace(cultureName, nameof(cultureName));

        UiCultureName = !uiCultureName.IsNullOrWhiteSpace()
            ? uiCultureName
            : cultureName;

        DisplayName = !displayName.IsNullOrWhiteSpace()
            ? displayName
            : cultureName;
        
        TwoLetterISOLanguageName = new CultureInfo(cultureName)
            .TwoLetterISOLanguageName;
    }
}