User Control as container at design time

Question

I\'m designing a simple expander control.

I\'ve derived from UserControl, drawn inner controls, built, run; all ok.

Since an inner Control is a Panel, I\'d l

Answer 1

ParentControlDesigner doesn't know what you want do. It only knows you want your UserControl to be a container.

What you need to do is implement your own designer which enables design mode on the panel:

    using System.ComponentModel;
    using System.Windows.Forms;
    using System.Windows.Forms.Design;

    namespace MyCtrlLib
    {
        // specify my custom designer
        [Designer(typeof(MyCtrlLib.UserControlDesigner))]
        public partial class UserControl1 : UserControl
        {
            public UserControl1()
            {
                InitializeComponent();
            }

            // define a property called "DropZone"
            [Category("Appearance")]
            [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] 
            public Panel DropZone
            {
                get { return panel1; }
            }
        }

        // my designer
        public class UserControlDesigner  : ParentControlDesigner
        {
            public override void Initialize(System.ComponentModel.IComponent component)
            {
                base.Initialize(component);

                if (this.Control is UserControl1)
                {
                    this.EnableDesignMode(
                       (UserControl1)this.Control).DropZone, "DropZone");
                }
            }
        }
    }

I learned this from Henry Minute on CodeProject. See the link for some improvements on the technique.