btcpayserver/BTCPayServer/Models/StoreViewModels/WalletModel.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc.Rendering;

namespace BTCPayServer.Models.StoreViewModels
{
    public class WalletModel
    {
        public string ServerUrl { get; set; }
        public SelectList CryptoCurrencies { get; set; }
        [Display(Name = "Crypto currency")]
        public string CryptoCurrency
        {
            get;
            set;
        }

        class Format
        {
            public string Name { get; set; }
            public string Value { get; set; }
        }
        public void SetCryptoCurrencies(ExplorerClientProvider explorerProvider, string selectedScheme)
        {
            var choices = explorerProvider.GetAll().Select(o => new Format() { Name = o.Item1.CryptoCode, Value = o.Item1.CryptoCode }).ToArray();
            var chosen = choices.FirstOrDefault(f => f.Name == selectedScheme) ?? choices.FirstOrDefault();
            CryptoCurrencies = new SelectList(choices, nameof(chosen.Value), nameof(chosen.Name), chosen);
            CryptoCurrency = chosen.Name;
        }
    }
}