Tasks: How To Catch Exceptions Thrown During Task Processing

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C#

Visual-Studio

WinForms

C#4.0

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Good day all!!!

I have been struggling with understanding tasks.
I have a login form that has an authenticating gif that is displayed when the user clicks the login button. I decided to use a task so that the form ui doesn't freeze while attempting to login. I will add the code below.
My first question is:

01. Is my coding right :)

02. If there is an error while attempting to login (server side); how do I pass a custom exception message from the server to the task exception, so that I can access it using

result.Exception.Message

03. After some browsing and asking, I'm wondering if it would be better to use a BackgroundWorker. And if so, how would I go about doing that.

Thanx in advance for you help...

    List<SqlParameter> _SqlParameter = new List<SqlParameter>(7);
    CancellationTokenSource tokenSource = new CancellationTokenSource();
    CancellationToken token = tokenSource.Token;

    token.ThrowIfCancellationRequested();

    Task.Factory.StartNew(() =>
    {
        //bsiLoginStatus.Caption = "Authenticating...";

        SetBarStaticItemValue(bsiLoginStatus, "Authenticating...", ClaimCatch_Lite.Properties.Resources.loading);

        try
        {
            _SqlParameter.Add(new SqlParameter("@User_UserName", SqlDbType.VarChar, 50));
            _SqlParameter.Add(new SqlParameter("@User_Password", SqlDbType.VarChar, 50));
            _SqlParameter.Add(new SqlParameter("@Station", SqlDbType.VarChar, 50));
            _SqlParameter.Add(new SqlParameter("@Users_RowID", SqlDbType.Int, 100, ParameterDirection.Output, false, 0, 0, string.Empty, DataRowVersion.Default, 0));
            _SqlParameter.Add(new SqlParameter("@Users_Name", SqlDbType.VarChar, 100, ParameterDirection.Output, false, 0, 0, string.Empty, DataRowVersion.Default, string.Empty));
            _SqlParameter.Add(new SqlParameter("@Success", SqlDbType.Bit, 1, ParameterDirection.Output, false, 0, 0, string.Empty, DataRowVersion.Default, 0));
            _SqlParameter.Add(new SqlParameter("@Default_Message", SqlDbType.VarChar, 200, ParameterDirection.Output, false, 0, 0, string.Empty, DataRowVersion.Default, string.Empty));

            _SqlParameter[0].Value = tbUsername.Text.Trim();
            _SqlParameter[1].Value = Encryption.EncryptData(tbPassword.Text.Trim());
            _SqlParameter[2].Value = Environment.MachineName.Trim();

            SqlDatabase.ExecuteReader("user_login", CommandType.StoredProcedure, _SqlParameter);

            GlobalClass.User_UserName = _SqlParameter[0].Value.ToString();
            GlobalClass.User_RowID = Convert.ToInt32(_SqlParameter[3].Value);
            GlobalClass.Users_Name = _SqlParameter[4].Value.ToString();
        }
        catch (Exception ex)
        {
            tokenSource.Cancel(true);
            DialogResult show = XtraMessageBox.Show(ex.Message, "Login Failed", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
        }
    }).ContinueWith(result =>
    {
        DialogResult show;

        switch (result.Status)
        {
            case TaskStatus.Canceled:
                SetBarStaticItemValue(bsiLoginStatus, result.Exception.Message, ClaimCatch_Lite.Properties.Resources.exclamation);
                show = XtraMessageBox.Show(result.Exception.Message, "Login Failed", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

                break;
            case TaskStatus.Faulted:
                SetBarStaticItemValue(bsiLoginStatus, result.Exception.Message, ClaimCatch_Lite.Properties.Resources.exclamation);
                show = XtraMessageBox.Show(result.Exception.Message, "Login Failed", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);

                break;
            case TaskStatus.RanToCompletion:
                if (Convert.ToBoolean(_SqlParameter[5].Value))
                {
                    CloseThis();

                    SetBarStaticItemValue(bsiLoginStatus, "Login successful...", ClaimCatch_Lite.Properties.Resources.accept);

                    Thread _ApplicationThread = new Thread(ShowApplication) { IsBackground = true, Name = "ApplicationThread" };
                    _ApplicationThread.Start();
                }
                else
                {
                    SetBarStaticItemValue(bsiLoginStatus, _SqlParameter[6].Value.ToString(), ClaimCatch_Lite.Properties.Resources.exclamation);
                    show = XtraMessageBox.Show(Convert.ToString(_SqlParameter[6].Value), "Login Failed", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                }

                break;
            default:
                SqlDatabase.DestroyConnectionString();
                Application.Exit();

                break;
        }
    },
        token,
        TaskContinuationOptions.None,
        TaskScheduler.FromCurrentSynchronizationContext());
}