VS 2005 Designer Error when dragging UserControl Onto Form

[Idev]

I created a form that uses Enterprise Library - DAAB - version Jan 2006 to access the DB in its constructor. Everything works fine; however, when I created a UserControl that attempts to store that form as a variable, the VS 2005 designer will not let me drag that UserControl onto a new form. It gives me the following error:


“Failed to create component ‘UserControl’. The error message follows: ‘System.NullReferenceException: Object reference not set to an instance of object. At Microsoft.Practices.EnterpriseLibrary.Data.DatabaseConfigurationView.get_DefaultName(), at Microsoft.Practices.EnterpriseLibrary.Data.DatabaseMapper.MapName(String name, IConfigurationSource configSource)……. "


Everything compiles successfully without errors; however, I am unable to drag the UserControl on any forms. After debugging, I found that the error is caused by the line “Database db = DatabaseFactory.CreateDatabase();”

I feel that being able to store forms that use DAAB inside UserControls is a reasonable requirement.


Any help would be appreciated! Thanks in advance!


Below is the relevant code:

public partial class SampleControl : UserControl
{
private ProductForm subForm = new ProductForm();
public SampleControl ()
{
InitializeComponent();
}
}

public partial class ProductForm : Form
{
public ProductForm()
{
InitializeComponent();
AccessDB();
}
private void AccessDB()
{
//THIS LINE CAUSES THE DESIGNER ERROR
Database db = DatabaseFactory.CreateDatabase();
}
}

 

[PlausiblyDamp]

Is the UserControl part of the same project as the form or is it a differerent project?

Also check your config files are correct - it could be failing to load it's configuration at design time and failing...

It may be worth wrapping the call to .CreateDatabase in a check and only run when not being called from the designer.