How to get design surface rendering and design time datasource selection with an asp.net user control

Question

If I create a user control (EDIT:not a web control/server control) it's pretty trivial to get databinding. I just add a datasourceID property.

In code behind (vb)

Partial Public Class BandedControl
    Inherits UserControl

    Public Property DataSourceID() As String
        Get
            Return MyGridView.DataSourceID
        End Get
        Set(ByVal value As String)
            MyGridView.DataSourceID = value
        End Set
    End Property

End Class

In code behind (c#)

public partial class BandedControl : UserControl
{

    public string DataSourceID {
        get { return MyGridView.DataSourceID; }
        set { MyGridView.DataSourceID = value; }
    }
}

My issue is that this breaks design time rendering and also I don't get a drop down list to choose my datasource. How do I resolve this. (Hint: I think I need a type convertor, but all the info I can find relates to server controls not user controls).

Answer 1

Web UserControls are compiled dynamically at run time and so are not rendered at Design time, what you want to do is create a Web Custom Control. Your best bet here is to extend one of the existing Bindable Web Controls

http://msdn.microsoft.com/en-us/library/aa651710(VS.71).aspx

Answer 2

You could try adding the IDReferenceProperty attribute to your property definition...

public partial class BandedControl : UserControl
{
    [System.Web.UI.IDReferenceProperty(typeof(DataSourceControl))]
    public string DataSourceID
    {
        get
        {
           return MyGridView.DataSourceID;
        }
        set
        {
           MyGridView.DataSourceID = value; 
        }
    }
}

See http://msdn.microsoft.com/en-us/library/system.web.ui.idreferencepropertyattribute.aspx for more info about the IDReferencePropertyAttribute class.

If that doesn't work - I'd also try to inherit from DataBoundControl instead of UserControl and see if that gets you anywhere.

Answer 3

Not sure if this is exactly what you want but I seem to remember them showing something similar to this in some dnr tv episodes.

I think it was Miguel Castro episodes 1 & 2, but it could be episode 31.

An archive of all the videos is here