Configuring log4net TextBoxAppender (custom appender) via Xml file

Question

This is in followup to my question: Flexible Logging Interface...

I now want to write a custom log4net appender for a multiline TextBox, for my WinForms 2.0 applicat

Answer 1

here is an updated version of all upper comments: thread safe, doesn't lock the application and uses the conversion pattern:

namespace MyNamespace
{

    public class TextBoxAppender : AppenderSkeleton
    {
        private TextBox _textBox;
        public TextBox AppenderTextBox
        {
            get
            {
                return _textBox;
            }
            set
            {
                _textBox = value;
            }
        }
        public string FormName { get; set; }
        public string TextBoxName { get; set; }

        private Control FindControlRecursive(Control root, string textBoxName)
        {
            if (root.Name == textBoxName) return root;
            foreach (Control c in root.Controls)
            {
                Control t = FindControlRecursive(c, textBoxName);
                if (t != null) return t;
            }
            return null;
        }

        protected override void Append(log4net.Core.LoggingEvent loggingEvent)
        {
            if (_textBox == null)
            {
                if (String.IsNullOrEmpty(FormName) ||
                    String.IsNullOrEmpty(TextBoxName))
                    return;

                Form form = Application.OpenForms[FormName];
                if (form == null)
                    return;

                _textBox = (TextBox)FindControlRecursive(form, TextBoxName);
                if (_textBox == null)
                    return;

                form.FormClosing += (s, e) => _textBox = null;
            }
            _textBox.BeginInvoke((MethodInvoker)delegate
            {
                _textBox.AppendText(RenderLoggingEvent(loggingEvent));
            });
        }
    }

}

The configuration, place this in app.config: