ASP.NET DropDownList 的层级绑定

先创建一个绑定函数 private void BindClass()     {         var convertDal = new BaseConvertDal<ProType>();         IEnumerable<ProType> list = convertDal.GetAllObjects("");         if (list.Count() == 0)         {             return;         }         IEnumerable<ProType> iList = from proType in list where proType.ProParentID == int.Parse(ClassId) select proType;         foreach (ProType proType in iList)         {             var li = new ListItem(proType.ProTypeName, proType.ProTypeID.ToString());             ddlClassType.Items.Add(li);             DropDownListBoind("", proType.ProTypeID, list, 1, ddlClassType);         }         if (!String.IsNullOrEmpty(ClassValue))         {             ddlClassType.Items.FindByValue(ClassValue).Selected = true;         }     } 创建DropDownList的循环绑定 public void DropDownListBoind(string pading, int dirId, IEnumerable<ProType> list, int deep, DropDownList list1) { IEnumerable<ProType> iList = from proType in list where proType.ProParentID == dirId select proType; foreach (ProType proType in iList) { string strPading = ""; for (int j = 0; j < deep; j++) { strPading += "　"; //用全角的空格 } //添加节点 var li = new ListItem(strPading + "├ " + proType.ProTypeName, proType.ProTypeID.ToString()); //将要显示在DropDownList里面的文本和值(name,value)添加到DropDownList里面 list1.Items.Add(li); DropDownListBoind(strPading, Convert.ToInt32(proType.ProTypeID), list, deep + 1, list1); //递归调用 } }