Question

I have an application that consists of two forms. One form displays data returned from the database in fields and the other form opens a windows that allows the user to select which database to get the data from.

Currently, the application doesn’t store the user’s choice of database. I want to store what the currently selected connection string is each time the user selects the database they want to use in form2.

What is the best way to do this? If I made an instance of an object of a static class to store this information, would that persist the data for use on each form?

Answer 1

Though there are built-in .NET capabilites to store user related information (via Registry, config files, settings etc.) they seem to be too heavy.

I would recommend to use plain text file and keep it in user folder:

var userPath = Environment.GetFolderPath(Environment
                                             .SpecialFolder.ApplicationData);
var filename = Path.Combine(userPath, "mysettings");

// Read connection string
var connectionString = File.ReadAllText(filename);

// Write connection string
File.WriteAllText(filename, connectionString);

Also note that hardly users will have fun working with connection strings. They would prefer to specify database name, server, username etc. using separate form fields. To map those fields to connection string you may use SqlConnectionStringBuilder class (if you are working with MSSQL Server):

// to connection string
var connectionStringBuilder1 = new SqlConnectionStringBuilder();
connectionStringBuilder1.DataSource = "server";
connectionStringBuilder1.InitialCatalog = "database";
var connectionString = connectionStringBuilder1.ConnectionString;

// from connection string
var connectionStringBuilder2 = new SqlConnectionStringBuilder(connectionString);
var serverName = connectionStringBuilder2.DataSource;
var databaseName = connectionStringBuilder2.InitialCatalog;