SharePoint Text Filter Consumer

namespace FilteredWebPart.SampleFilterWebPart
{
    [ToolboxItemAttribute(false)]
    public class SampleFilterWebPart : WebPart
    {
        private string addedString;

        protected override void CreateChildControls()
        {
            if (string.IsNullOrEmpty(this.addedString))
            {
                this.Controls.Add(new LiteralControl("Salut !"));
            }
            else
            {
                this.Controls.Add(new LiteralControl(string.Format("Tu crois vraiment que je vais chercher '{0}' pour toi ?", this.addedString)));
            }
        }

        [ConnectionConsumer("filter")]
        public void SetFilter(IWebPartField filterValues)
        {
            if (filterValues != null)
            {
                FieldCallback callback = new FieldCallback(ReceiveField);
                filterValues.GetFieldValue(callback);
            }
            else
            {
                this.addedString = string.Empty;
            }
        }

        public void ReceiveField(object objField)
        {
            if (objField != null)
            {
                this.addedString = (string)objField;
            }
        }

    }
}