CryptoExchange.Net/Examples/BlazorClient/Pages/SpotClient.razor

@page "/SpotClient"
@using CryptoExchange.Net.SharedApis
@using System.Diagnostics
@inject IEnumerable<ISpotTickerRestClient> restClients

<h3>ETH-BTC prices:</h3>
@foreach(var price in _prices.OrderBy(p => p.Key))
{
    <div>@price.Key: @price.Value</div>
}

@code{
    private Dictionary<string, decimal?> _prices = new Dictionary<string, decimal?>();

    protected override async Task OnInitializedAsync()
    {
        var symbol = new SharedSymbol(TradingMode.Spot, "ETH", "BTC");
        var tasks = restClients.Select(x => x.GetSpotTickerAsync(new GetTickerRequest(symbol)));
        await foreach (var ticker in ParallelEnumerateAsync(tasks))
        {
            if (ticker.Success)
                _prices.Add(ticker.Exchange, ticker.Data.LastPrice);
            else
                Debug.WriteLine($"{ticker.Exchange} failed: {ticker.Error}");

            await InvokeAsync(StateHasChanged);
        }
    }

    private async IAsyncEnumerable<T> ParallelEnumerateAsync<T>(IEnumerable<Task<T>> tasks)
    {
        var remaining = new List<Task<T>>(tasks);

        while (remaining.Count != 0)
        {
            var task = await Task.WhenAny(remaining).ConfigureAwait(false);
            remaining.Remove(task);
            yield return task.Result;
        }
    }

}