Accessing database connection string using app.config in C# winform

Question

I can\'t seem to be able to access the app.config database connection string in my c# winforms app.

app.config code

Answer 1

SqlConnection conn = new SqlConnection();
conn.ConnectionString = ConfigurationManager
    .ConnectionStrings["MyDBConnectionString"].ConnectionString;
try
{
    conn.Open();                
}
catch (Exception)
{
    throw;                    
}