MultiThreading in WinForms C#

Question

I am newbie and i learned alot of things from StackOverflow. I recently started using threading in my windows application. As far as i heard multi-threading makes things easy, like doing alot of event at the same time.

I have Stored procedures in SQL and I call then in few methods.

here is my code

private void EditCustomer_Load(object sender, EventArgs e)
        {
            screenszize_Location();

            Thread BackgroundThread = new Thread
                (
                new ThreadStart(() =>
                {
                    GridCustomerList.BeginInvoke(
                     new Action(() =>
                     {
                         LoadGrid();
                     }
                     ));
                }

                ));
            BackgroundThread.Start();


            Thread BackgroundThread1 = new Thread
                (
                new ThreadStart(() =>
                {
                    ComboBxVechicleNumber.BeginInvoke(
                     new Action(() =>
                     {
                         LoadVnum();
                     }
                     ));
                }


                ));
            BackgroundThread1.Start();

            Thread BackgroundThread2 = new Thread
                (
                new ThreadStart(() =>
                {
                    ComboBxBikeMake.BeginInvoke(
                     new Action(() =>
                     {
                         loadBikeMake();
                     }
                     ));
                }


                ));
            BackgroundThread2.Start();

        }

What this does is, * Screen Layout * Loads a 3 column Grid wit some 2000 rows * Loads Vehicle numbers from SQL table into a Combobox. * Loads Bike Names from SQL table into a Combobox.

My Computer is fast has best performance, but still The Form which i load freezes and becomes WHITE for couple of seconds and then a loads.

Am I doing the whole threading thing wrong ?

Answer 1

Thanks to @mrlucmorin and Drik and TomTom and Every1

Hea is My Code Again.

private void LoadGrid()
        {
            Thread BackgroundThread = new Thread
                (
                new ThreadStart(() =>
                {
                    ConnectionStringSettings consetting = ConfigurationManager.ConnectionStrings["AutoDB"];

                         String ConnectionString = consetting.ConnectionString;

                         SqlConnection con = new SqlConnection(ConnectionString);

                             SqlCommand command = new SqlCommand();
                             DataSet ds = new DataSet();
                             SqlDataAdapter da = new SqlDataAdapter();

                             int i = 0;

                             con.Open();
                             command.Connection = con;
                             command.CommandType = CommandType.StoredProcedure;
                             command.CommandText = "LoadAllCustomers";


                             da.SelectCommand = command;
                             da.Fill(ds, "dbo.TblCustomers");

                    GridCustomerList.BeginInvoke(
                     new Action(() =>
                     {

                         GridCustomerList.DataSource = ds.Tables["dbo.TblCustomers"];

                     }
                     ));
                }

                ));
            BackgroundThread.Start();


        }

It works Perfectly as expected :)

Answer 2

You don't show your LoadGrid method definition, but I guess it fetches data from the DB, and then sets the DataSource on a DataGridView or BindingSource.

You should split those 2 steps such that only the setting of the DataSource is done on the UI thread, and the fetching of the data still happens in the BackgroundThread.

Something like this:

Thread BackgroundThread = new Thread
(
new ThreadStart(() =>
{
    //Fetch data here
    GridCustomerList.BeginInvoke(
     new Action(() =>
     {
         //Set DataSource here
     }
     ));
}

));

Cheers