Using classes to sanitaze code

Hello,

I was thinking to post this in WPF forum, but to the best of my knowledge this is pure c# issue.

I have application (WPF) that display values in listbox. I am using SQLite. On the form I have simple buttons named: ADD, EDIT and DELETE. So, just a simple ordinary page.

Every buttons carries a connection code:

 SQLiteConnection conn = new SQLiteConnection(@"data source=...\Debug\bazaa.s3db");
            conn.Open();

            SQLiteCommand cmd = new SQLiteCommand(" Select * from korisnici", conn);

            DataSet1 dt = new DataSet1();

            SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);

            DataTable tbl = new DataTable();
            da.Fill(tbl);
            
            // fill the listview with values
            listView1.DataContext = tbl;
            conn.Close();

You can imagine how ugly does it luck having code repetition, so I thought to use classes.

I tried making a static class with a method that contains the above mentioned code. Problem is tbl value. I cant return a tbl. I tried converting it to string and returning it. That works, but string shows nothing.

After thinking i come to an idea to have to classes. First class will be called from main code and will contain this:

 public  class konekcija
    {
        ListView zomg = new ListView(); // this list view will be copied onto another class
        
         public void konektujme()
       {
           
           
       
             SQLiteConnection conn = new SQLiteConnection(@"data source=...\Debug\bazaa.s3db");
           conn.Open();

           SQLiteCommand cmd = new SQLiteCommand(" Select * from korisnici", conn);

           DataSet1 dt = new DataSet1();

           SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);

           DataTable tbl = new DataTable();
           da.Fill(tbl);
           //listView1.DataContext = tbl;
           
           zomg.DataContext = tbl;
           elementi.transfer.DataContext = zomg.DataContext;
           conn.Close();
           
       }

Also i thought to create additional static class, in which I will have only this:

static public class elementi 
    {

        static public ListView transfer = new ListView();
        
    }

And in main code do this:

  konekcija jao = new konekcija();
            jao.konektujme();
            listView1.DataContext = elementi.transfer;

Please help me with this. I might be close to solution or totally in wrong direction, I really do not know.
Can you please provide me with your solution, or point me to errors in my solution.

Much appreciated.

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

vedran16y ago
thank you for your reply.

I got this sorted now :)

Aaron Colen16y ago

For most of my projects that include database access I just create 1 static class with all the db methods. It may not be the best/most correct way but it's worked for me so far.

ie

public static class DataAccess
{
    private static SQLiteConnection conn = new SQLiteConnection("Connection String");

    public static DataTable Method1()
    {        
        DataTable tbl = new DataTable();
        SQLiteCommand cmd = new SQLiteCommand(" Select * from korisnici", conn);
        conn.Open();                
        SQLiteDataAdapter da = new SQLiteDataAdapter(cmd);
        da.Fill(tbl);
        conn.Close();
        return tbl;
    }
}

And then from your button:

DataTable tbl = DataAccess.Method1();
listView1.DataContext = tbl;