Datagrid view is not refreshing by itself

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C#

WinForms

Actually, when I click on the rows or cells of the datagrid view, they are populating into the text boxes to edit, after I editing and clecked on the update, the datagridview is not changing instantly, if I close and run the form again, it is changing. My requirement is it should change immediately after I click on the update button. The code I am using for update click is:

private void btnUpdate_Click(object sender, EventArgs e)
       {

           SqlConnection con = Helper.getconnection();
           SqlCommand cmd = new SqlCommand();
           cmd.Connection = con;
           cmd.CommandType = CommandType.Text;
           string PrjID = txtPrjID.Text;
           string PrjName = txtPrjNmae.Text;
           string Description = txtPrjdescription.Text;
           string Date = txtPrjDate.Text;
           string Size = txtPrjSize.Text;
           string Manager = txtPrjManager.Text;
           cmd.CommandText = "Update Projects set ProjectName= '" + PrjName + "', Description='" + Description + "', DateStarted='" + Date + "',TeamSize='" + Size + "',Manager='" + Manager + "' where ProjectID= " + PrjID + " ";
           MessageBox.Show("Project Details are updated");
           dataGridView2.Update();
           dataGridView2.Refresh();
           con.Open();
           cmd.ExecuteNonQuery();
           con.Close();

           }