Question

I have some WebUserControls that take a parameter to determine how they initialize themselves. However, when I compile the page I get the error

'ControlName' does not contain a constructor that takes '0' arguments

I am not calling it anywhere without an argument, it appears that a reference is being generated in a temporary file. I have another control that doesn’t have a empty constructor and it is not requiring one to be created there so it shouldn’t have to have one.

The actual error looks like this:

Compiler Error Message: CS1729:

‘ControlName’ does not contain a
constructor that takes ‘0’ arguments

Source Error:

Line 108: private static bool
@__initialized; Line 109: Line
110:
[System.Diagnostics.DebuggerNonUserCodeAttribute()]
Line 111: public control_ascx()
{ Line 112:
((global::ControlNamespace)(this)).AppRelativeVirtualPath
= “~/ControlName.ascx”;

Source File:
(Path)Local\Temp\Temporary ASP.NET
Files\root\1aca8e08\3fab105e\App_Web_controlname.ascx.cdcab7d2.tzm0xzkd.0.cs
Line: 110

The control looks like this:

public partial class ControlName: System.Web.UI.UserControl
{
    public ControlName(IParameter parameter)
    {
        Method(parameter);
    }
}

EDIT: Based on the comments below it would appear that I have a reference to the control in a designer file…somewhere… All references that I can find are located in code behinds with one exception. The declaration in the .ascx file:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="ControlName.ascx.cs" Inherits="Control" %>

I thought that this was the culprit but upon further inspection I have other controls which have a similar declaration and do NOT require a default constructor.

How can I find the location where the control is referenced from?

Solution:

I had reference tags

<%@ Reference Control="~/ControlName.ascx" %>

leftover from earlier that apparently count as a designer element.

The answer below does not actually contain this information but is a good description of what the problem was.

Answer 1

I’m no expert on web development, but it looks like you’ve got an instance of the control placed on a web form designer, and that designer is generating code that expects a parameterless constructor.

If this is the case, then to solve this problem, you should either remove the control from the form or add a parameterless constructor.