Base class includes field but type not compatible with type of control

Question

The base class includes the field 'lbl', but its type (web.App_Code.CustomLabelControl) is not compatible with the type of control (web.App_Code.CustomLabelControl).

I had done many custom controls before the same way but today I ran into this error.

I have a web application project with the below class in App_Code directory a tagprefix reference in web.config for the control in class.

What do I do now?

Web.Config

<system.web>
    <pages>
        <controls>
            <add namespace="web.App_Code" tagPrefix="CControls"/>...

Markup

<form id="form1" runat="server">
<div>
    <CControls:CustomLabelControl runat="server" OnClickText="Welcome" ID="lbl">
    </CControls:CustomLabelControl>
</div>
</form>

Class File

namespace web.App_Code
{
    public class CustomLabelControl : Control, IPostBackEventHandler, IPostBackDataHandler
    {
        private string _onClickText;

        public CustomLabelControl()
        {

        }

        public string OnClickText
        {
            get { return _onClickText; }
            set { _onClickText = value; }
        }

        public void RaisePostBackEvent(string eventArgument)
        {
            throw new System.NotImplementedException();
        }


        public bool LoadPostData(string postDataKey, NameValueCollection postCollection)
        {
            throw new System.NotImplementedException();
        }


        public void RaisePostDataChangedEvent()
        {
            throw new System.NotImplementedException();
        }
    }
}

I've checked these resources already:

• The base class includes the field 'btnLogin', but its type (FoodOrder.App_Code.LinkButtonDefault) is not compatible

• http://support.microsoft.com/kb/919284

• Base class includes the field 'X', but its type (System.Web.UI.ScriptManager) is not compatible with the type of control (System.Web.UI.ScriptManager)

Answer 1

Try specifying the assembly name too:

<add tagPrefix="CControls" namespace="web.App_Code" assembly="web.App_Code" />

I would consider creating a dedicated namespace for your custom controls, just for the sake of clarity. Maybe something like web.App_Code.CustomControls:

<add tagPrefix="CControls" namespace="web.App_Code.CustomControls" assembly="web.App_Code.CustomControls" />

Answer 2

Unckeck the build (and publish) option "Allow this precompiled site to be updatable"

It might not be enought for the runtime, so check the option "use fixed naming and single page assemblies" and it solved my case :)

here is a useful link about this error: http://forums.asp.net/t/960707.aspx