How to access inherited controls in the winforms designer

Question

I'm making some controls which all have to share the same look and some common behavior, although they are meant for different kind of inputs. So I made a BaseClass which inherit from UserControl, and all my controls inherit from BaseClass.

However, if i add controls for BaseClass in the designer, such as a TableLayoutPanel, i can't access them when I'm designing the inherited classes. I see the TableLayoutPanel, but even though he is "protected", i can't modify it or put controls in it through the designer. I've no trouble accesing it by code, but i don't want to lose the ability to use the designer.

Right now, i simply removed all controls from BaseClass, added the layout and all the common controls in each of the inherited class, then use references to manipulate them inside BaseClass. But that doesn't satisfy me at all. Is there a way to make the designer work with inherited protected member controls ?

Environment : C#, .NET 3.5, Visual Studio 2008

EDIT to answer SLaks's suggestion. I tried setting a property, and although I'm not used to use them it doesn't seem to work. Here is the code i tried :

    public partial class UserControl1 : UserControl
    {
            public UserControl1()
            {
                    InitializeComponent();
            }

            public TableLayoutPanel TableLayoutPanel1
            {
                    get { return tableLayoutPanel1;}
                    set { tableLayoutPanel1 = value;}
            }
    }

    public partial class UserControl2 : UserControl1
    {
            public UserControl2()
            {
                    InitializeComponent();
            }
    }

Solution 1

When you try to access from the inherited control with the designer to the TableLayoutPanel declared in the base control, you're using a feature in WinForms called "Visual Inheritance".

Unfortunately TableLayoutPanel doesn't support visual inheritance: http://msdn.microsoft.com/en-us/library/ms171689%28VS.80%29.aspx

That's why the TableLayoutPanel appears blocked in the inherited controls.

Solution 2

Try adding this attribute to the definition of the panel (this may or may not help):

[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]

Comments

[Ksempac]

Setting the rows, columns and size of a TableLayoutPanel in the base class is what i would like to do. But it's pointless if i can't add controls in the layout when I'm designing the derived class. For example having a blank cell in my tablelayout, and then add, through the designer, a different control in each of the derived class in this cell.

[SLaks]

Try making the field private, and adding that attribute to a public property exposing it.

[SLaks]

That is what SplitContainer does

[Shea]

You can't modify the base control while designing the derived control. Not easily anyway. If you made the "empty spaces" public (e.g., EmptyPanel1, EmptyPanel2, ...) then provided your own TypeEditor for them you can at least allow them to set the controls visually. Creating a type editor is a bit of work though.

[Jacobs Data Solutions]

I ran straight into this problem. FTA: "Use the TableLayoutPanel control sparingly."

[garaber]

Yes this look like a dead end. I was able to find most of the C# source for tablelayout and the designer but it looks like I will never find the FlowPanelDesigner.uex files associated with this control