protected void TreeBind() { var categoryIdTitleMap = new Agp2pDataContext().dt_article_category.Where(c => c.channel_id == 6).OrderBy(c => c.sort_id).ToDictionary(c => c.id, c => c.title); ddlCategoryId.Items.Clear(); ddlCategoryId.Items.Add(new ListItem("所有产品", "")); ddlCategoryId.Items.AddRange(categoryIdTitleMap.Select(c => new ListItem(c.Value, c.Key.ToString())).ToArray()); if (categoryId > 0) { ddlCategoryId.SelectedValue = categoryId.ToString(); } }