how to refresh a data grid?

i m using c# as front end and ms access as back end

I m displaying the datagrid only when the index in the combo box is changed

 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        refershGridView(comboBox1.Text);
    }

but when I make any updates to the data grid ,the update reflects only after i make a selected index change event

i tried datagidview1.refresh() and also called my refershGridView(comboBox1.Text) functions implicitly

but my grid view refreshes only when i make a selected index change

code for refershGridView(comboBox1.Text)

private void refershGridView(string tableName)
    {

        saveBttnSwitch = 0;//for save button swicth 
        //setting back to intial user interface ..



        clearVisibilty();
        clearall();
        button1.Visible = true;
        button3.Visible = false;

        label11.Visible = false;
        try
        {
            OleDbConnection mycon = new OleDbConnection();

            mycon.ConnectionString = ConnString;

            //create the database query
            string query = null;
            if (tableName == "employee")
            {
                query = "SELECT fname,lname,ssn FROM employee";

                dataGridView1.Visible = true;
            }
            if (tableName == "project")
            {


                query = "SELECT pname,pnumber FROM project";

                dataGridView1.Visible = true;

            }



            //create an OleDbDataAdapter to execute the query
            OleDbDataAdapter dAdapter = new OleDbDataAdapter(query, mycon);


            //create a command builder
            OleDbCommandBuilder cBuilder = new OleDbCommandBuilder(dAdapter);

            //create a DataTable to hold the query results
            DataTable dTa开发者_Go百科ble = new DataTable();

            //fill the DataTable
            try
            {
                dAdapter.Fill(dTable);
            }

            catch (OleDbException exp)
            {
                label11.Text = "file couldnt be found...kindly check Db file location ";
                label11.Visible = true;
                button1.Visible = false;

            }
            //  DataGridView dgView = new DataGridView();

            //BindingSource to sync DataTable and DataGridView
            BindingSource bSource = new BindingSource();

            //set the BindingSource DataSource
            bSource.DataSource = dTable;

            //set the DataGridView DataSource
            dataGridView1.DataSource = bSource;
            // dataGridView1.Dock = DockStyle.Fill;
            dataGridView1.AutoGenerateColumns = true;

            mycon.Close();
        }
        catch (System.Data.SqlClient.SqlException ex)
        {

            throw new InvalidOperationException("Data could not be read", ex);

        }

        this.button2.Visible = false;

    }

Does refershGridView(comboBox1.Text); refill the DataGrid?

If so, call it from any other place where you want your data to be refilled. If SelectedIndexChanged even of the combo is the only place you are filling it, it won't refresh unless you change a selection.

And as @Bryan suggests, its better if we see some code.

Try to clear the dTable and dataGridView1.DataSource before you fill the DataTable and sets the DataGridView DataSource

dTable = new DataTable();
dataGridView1.DataSource = nothing;