protected void ASPxGridView1_CustomCallback(object sender, DevExpress.Web.ASPxGridViewCustomCallbackEventArgs e)
    {
        ASPxGridView thisASPxGridView = sender as ASPxGridView;

        foreach (GridViewColumn column in thisASPxGridView.Columns)
        {
            GridViewDataColumn dataColumn = column as GridViewDataColumn;
            if (dataColumn == null)
            {
                continue;
            }
            ASPxTextBox filterCellTextBox = thisASPxGridView.FindFilterCellTemplateControl(dataColumn, "ASPxTextBox1") as ASPxTextBox;
            if (filterCellTextBox == null)
            {
                continue;
            }
            if (e.Parameters == "clear")
            {
                filterCellTextBox.Text = string.Empty;
            }
            thisASPxGridView.AutoFilterByColumn(dataColumn, filterCellTextBox.Text);
        }
    }