C#

var dbCredentialsFormDI = serviceProvider.GetRequiredService<DbCredentialsForm>();
dbCredentialsFormDI.firstTime = false;
dbCredentialsFormDI.Dock = DockStyle.None;
dbCredentialsFormDI.StartPosition = FormStartPosition.CenterScreen;

var result = dbCredentialsFormDI.ShowDialog();
if (result == DialogResult.OK)
{
    Application.DoEvents();
}

public partial class DbCredentialsForm : Form
{
    private readonly bool _firstTime;

    public DbCredentialsForm(bool firstTime)
    {
        InitializeComponent();
        _firstTime = firstTime;
        OK_Button.Enabled = false;
    }

public partial class DbCredentialsForm : Form
{
    public bool firstTime { get; set; }

    public DbCredentialsForm()
    {
        InitializeComponent();           
       OK_Button.Enabled = false;
    }

public class Foo
{
    public IBar Bar { get; }
    public IBaz Baz { get; }
    public Foo(IBar bar = default, IBaz baz = default) (Bar, Baz) = (bar, baz);
}

...

IServiceCollection services = new ServiceCollection();
services.AddTransient<IBaz, Baz>();
services.AddTransient<Foo>();

IServiceProvider provider = services.BuildServiceProvider();
Foo foo = provider.GetRequiredService<Foo>();

Debug.Assert(foo != null);
Debug.Assert(foo.Baz != null);
Debug.Assert(foo.Bar == null);

using static System.Console;
...
WriteLine("Foo"); // Calls System.Console.WriteLine("Foo");

Richard Deeming wrote:

of that type available with prefixing them

contents = await client.GetStringAsync(url);
var res2 = JsonConvert.DeserializeObject<RootObject>(contents.ToString());
if (180 == res2.content.Count)
{
    StoredDates.Add(date, contents);
    StoredDatesList = JsonConvert.SerializeObject(StoredDates, Formatting.Indented);
}

public static string StoredDatesList
        {
            get => Preferences.Get(nameof(StoredDatesList), string.Empty);
            set => Preferences.Set(nameof(StoredDatesList), value);
        }
        public static async Task<string> GetDraws(Uri url, string date)
        {
            var StoredDates = JsonConvert.DeserializeObject<Dictionary<string, string>>(StoredDatesList);
            var contents = string.Empty;
            var current = Connectivity.NetworkAccess;
            var client = new HttpClient();

            if (StoredDates != null)
                if (StoredDates.ContainsKey(date))
                {
                    contents = StoredDates[date];
                }
                else
                {
                    if (current != NetworkAccess.Internet)
                        return Helpers.Settings.Common_Error_NoInternetConnection;

                    contents = await DownloadResults(url, date, StoredDates, contents, client);
                }
            else
            {
                if (current != NetworkAccess.Internet)
                    return Helpers.Settings.Common_Error_NoInternetConnection;

                StoredDates = new Dictionary<string, string>();
                contents = await DownloadResults(url, date, StoredDates, contents, client);
            }
            return contents;
        }

        private static async Task<string> DownloadResults(Uri url, string date, Dictionary<string, string> StoredDates, string contents, HttpClient client)
        {
            contents = await client.GetStringAsync(url);
            var res2 = JsonConvert.DeserializeObject<RootObject>(contents.ToString());
            if (180 == res2.content.Count)
            {
                StoredDates.Add(date, contents);
                StoredDatesList = JsonConvert.SerializeObject(StoredDates, Formatting.Indented);
            }

            return contents;
        }

...
public const string Common_Error_NoInternetConnection = "Error_NoInternetConnection";