Question

A nice chap called Darin kindly provided me with some code in order for me to retrieve an image by its file path.

However, when I attempt to execute the code, I receive a “NullReferenceException was unhandled by user code; Use the ‘new’ keyword to create an object instance” on the first var line.

The code can be found below:

   var connectionString = ConfigurationManager.ConnectionStrings["SomeCN"].ConnectionString;
        using (var cn = new SqlConnection("Data Source=STRSQL04;Initial Catalog=PDC;Integrated Security=True"))
        using (var cmd = cn.CreateCommand())
        {
            cn.Open();
            cmd.CommandText = "Select imageID from accounts where MemberID = FM00012";
            cmd.Parameters.AddWithValue("FM00012",5);
            using (var reader = cmd.ExecuteReader())
            {
                if (reader.Read())
                {
                    var filepath = reader.GetString(0);
                Image1.ImageUrl = filepath;
                }
            }
        }

Can someone point out the error in my ways please?

Apologies as always for asking, what I suspect are, ridiculous questions.

Answer 1

You don’t have a connection string called “SomeCN” (or whatever you’re using for real) in your app config, so when you try to access the ConnectionString.ConnectionString parameter, it throws a nullref.

Can you post the contents of your app.config, or at least the ConnectionStrings element, so we can see?

• Modifying application settings on MSDN (when you try it, you’ll see one of the settings types in the dropdown of the settings editor is “ConnectionString”).