Refreshing a DataGridView in C# via button click

Question

For some time now I have been trying to figure out how to refresh a datagridview in C# via a button click as currently I have been having to close and reopen the program to get it to update. I would like it so that once the user has added data or delete data, the datagridview is refreshed/updated to show the change. The data is stored in a MS Access database. I have tried using:

datagridview.Refresh();
datagridview.Update();

But it doesn't change anything.

Here is the code I have been using for when a user adds a new "player" and when a user deletes a "player"

private void btnAdd_Click(object sender, EventArgs e)
    {
        //This code uses the connection that was at the beginning of the form. It opens a connection to the MS Access database.
        connect.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\Users\Aaron\Documents\Cardfight Vanguard Tournament Program\Tournament\Tournament\Players.mdb";
        connect.Open();

        //This code creates a new command but at the same time tells the application where the data the user has inserted will be going.
        OleDbCommand cmd = new OleDbCommand("INSERT INTO Players VALUES (FirstName, LastName)", connect);

        //This blocks defines where the data will be coming from so the text box for the ISBN number is going too isbn.
        if (connect.State == ConnectionState.Open)
        {
            cmd.Parameters.Add("FirstName", OleDbType.VarChar, 20).Value = txtFirstName.Text;
            cmd.Parameters.Add("LastName", OleDbType.VarChar, 20).Value = txtLastName.Text;

            try
            {
                //Once that data has been stored a popup box will appear telling the user that it has been saved.
                cmd.ExecuteNonQuery();
                MessageBox.Show("Data Added", "Saved", MessageBoxButtons.OK, MessageBoxIcon.Information);

                txtFirstName.Clear();
                txtLastName.Clear();

                gridViewPlayers.Update();
                gridViewPlayers.Refresh();

                //This closes the connection to the MS Access database.
                connect.Close();

            }
            catch (Exception expe)
            {
                MessageBox.Show(expe.Source);
                connect.Close();
            }
        }
        else
        {
            //If for some reason the connection to the database should fail, a different pop up will appear telling the user it has failed.
            //It will then close the connection.
            MessageBox.Show("Connection Failed");
        }

        connect.Close();
        this.playersTableAdapter.Fill(this.playersDataSet.Players);

    }

    private void btnDelete_Click(object sender, EventArgs e)
    {
        connect.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\Users\Aaron\Documents\Cardfight Vanguard Tournament Program\Tournament\Tournament\Players.mdb";

        //This is where the string from the beginning of the application is called. It is used to temporarily store the data that is in txtFirstName.
        tempFirstName = txtFirstName.Text;

        connect.Open();

        //And then this command defines what row of data should be deleted.
        OleDbCommand cmd = new OleDbCommand("DELETE FROM Players WHERE FirstName ='" +tempFirstName+ "'", connect);

        cmd.ExecuteNonQuery();
        MessageBox.Show("Data Deleted", "Deleted", MessageBoxButtons.OK, MessageBoxIcon.Information);

        txtFirstName.Clear();
        txtLastName.Clear();

        connect.Close();
    }