Problem with clear controls in form

Here's the solution as you want ... work perfect :)

private void ClearFormControls(Control c, List<ComboBox> comboxNames)
{
    foreach (Control ctrl in c.Controls)
    {
        if (ctrl is TextBox)
        {
            ctrl.Text = "";
        }
        else if (ctrl is ComboBox)
        {
            int len = comboxNames.Count;
            for (int i = 0; i < len; i++)
            {
                if (ctrl.Name == (comboxNames[i].Name))
                {
                    ctrl.Text = "Choose an item";
                    comboxNames.RemoveAt(i);
                    len = len - 1;
                    break;
                }
                else
                {

                    if (!comboxNames.Contains(ctrl))
                    {
                        // if you bind from array use this.
                        (ctrl as ComboBox).Items.Clear();
                        (ctrl as ComboBox).Text = "";

                        // If you bind from data source use this.
                        //  (ctrl as ComboBox).DataSource = null;
                    }
                }


            }
        }

        else
        {
            if (ctrl.Controls.Count > 0)
            {
                ClearFormControls(ctrl , comboxNames);
            }

        }

    }
}

calling

List<ComboBox> seq = new List<ComboBox>();
           seq.Add(comboBox_AccountCategory);
           seq.Add(comboBox_CompanyName);
           seq.Add(comboBoxAge);
           seq.Add(comboBoxSalary);
           ClearFormControls(this, seq);

Your solution implies a need for a recursive parsing of the container object passed in to parameter Control 'c.

And, what you pass in here in the ArrayList parameter 'comboxNames is not the names of the ComboBoxes (that would imply strings), but a collection of references to the instances of ComboBox.

So, if you have, in advance, all the references to the ComboBoxes that require handling by the code you show here, I see no need for recursion to handle them.

On the other hand, your requirement, evidently, to set every TextBox's Text property to an empty string, appears to require recursion.

So I would decompose this into two solutions: a non-recursive one that just iterates your collection of ComboBox references and does what you need to do ...

And a second, recursive, solution to reset all the TextBoxes.

Now, if you had a situation where a bunch of TextBoxes all had the same name, but were all in different container objects, then .NET (2.0 and later) gives you the Controls.Find(string "ControlName," bool SearchAllChildren) method to return an array, and, obviously it can do a recursive search for you.

If you really had a whole bunch of TextBoxes, many in the same container (where they obviously must have unique names), or scattered across many containers, nested to whatever depth ...

I'd consider doing a recursive "walk" of the Form in the Form Load EventHandler where I built up a List<TextBox> to use later on for resetting them again, without possibly having to recurse more than once.

However, if you are adding controls at run-time, then that means that, as you create the new Controls, you need to add them to the list of either ComboBoxes, or TextBoxes ... if they require being handled as you show here. And, if they can be deleted at run-time: well, you figure that one out :)

best, Bill