使用c＃WinForm为内部面板创建DesignMode

Question

I have 2 panel in my Control.

panel 3 added to panel 1 for Title , panel 2 added to panel 1 For Content & panel 1 is My Control

I do create this Control For my Project . this Control Code:

public class ControWithTitle : Panel // Panel 1
{
    public Panel Title = new Panel { Dock = DockStyle.Top, Height = 20, BackColor = Color.Black }; // Panel 2
    public Panel Content = new Panel { Dock = DockStyle.Fill, BackColor = Color.White }; // Panel 3
    public ControWithTitle ()
        : base()
    {

        this.Controls.Add(Title);
        this.Controls.Add(Content);
    }
}

I do When Add This control in Form > Create Design Mode For Content . not panel 1 Or Title Panel....

this Code not Work ... All Panel is Lock . after Build Project , every Changed was reset...

is work this true? How to create this?

 ╔═══════════╗ < Paenl 1
 ║╔═════════╗║
 ║║ Panel 2 ║║
 ║╚═════════╝║
 ║╔═════════╗║
 ║║         ║║
 ║║         ║║
 ║║         ║║
 ║║ Panel 3 ║║ < Design Mode For This Paenl
 ║║         ║║
 ║║         ║║
 ║║         ║║
 ║╚═════════╝║
 ╚═══════════╝

after pasted Dear @King's Code My Problem Not Solved... This Error has in my project:

this is my Code for a Other Sample After (@Hans Passant & @King King) Answer:

    [Designer(typeof(CustomDesigner))]
public partial class ControlWithTitle : UserControl // Panel 1
{
    private System.ComponentModel.IContainer components = null;
    private ListView listView1 = new ListView();
    protected override void Dispose (bool disposing)
    {
        if (disposing && (components != null)) { components.Dispose(); }
        base.Dispose(disposing);
    }
    private void InitializeComponent ()
    {
        components = new System.ComponentModel.Container();
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.Controls.Add(listView1);
    }
    public Panel Title = new Panel { };
    public Panel Content = new Panel { };

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public ListView Employees { get { return listView1; } }

    public ControlWithTitle ()
    {
        InitializeComponent();
    }
}
public class CustomDesigner : ParentControlDesigner
{
    public override void Initialize (IComponent component)
    {
        ControlWithTitle control = Control as ControlWithTitle;
        if (control != null)
        {
            EnableDesignMode(control.Employees, "Employees");
        }
    }
}

Answer 1

You can try this code, you have to add reference to the System.Design.dll and using System.Windows.Forms.Design; :

[Desiner(typeof(CustomDesigner))]
public class ControWithTitle : Panel // Panel 1
{
   //....
}
public class CustomDesigner : ParentControlDesigner {
   public override void Initialize(IComponent component){
      ControWithTitle control = Control as ControWithTitle;
      if(control != null){
        //Enable designmode for Panel3
        EnableDesignMode(control.Content, "Content");
      }
   }
}