递归绑定ComboBox

	    /*递归方法*/	
            private void BindArea(string cityNo, int level, string pre)
		{
            List<AreaTInfo> cityList = new List<AreaTInfo>();
            foreach (AreaTInfo item in areaList)
            {
                if (item.F_AreaSN==cityNo.Trim())
                {
                    cityList.Add(item);
                }
            }
            string preStr = string.Empty;
            if (level > 0)
            {
                preStr +=pre+ "|";
                for (int i = 0; i < 2; i++)
                {
                    preStr += "-";
                }
            }
            int newye = level + 1;
            foreach (AreaTInfo item in cityList)
            {
                this.cmb_Area.Items.Add(preStr+new AreaInfo(item.AreaSN,item.AreaName).ToString());
                dic.Add(item.AreaSN,preStr+new AreaInfo(item.AreaSN,item.AreaName).ToString());
                BindArea(item.AreaSN, newye, preStr);
            }
        }
		
        Dictionary<string, string> dic = new Dictionary<string, string>();
        string _areaSN = string.Empty;
        /*ComboBox SelectedIndexChanged 事件*/
        private void cmb_Area_SelectedIndexChanged(object sender, EventArgs e)
        {
            string tmp = this.cmb_Area.SelectedItem.ToString();
            /*遍历Dictionary<string,string>*/
            foreach (KeyValuePair<string,string> item in dic)
            {
                if (item.Value==tmp)
                {
                    _areaSN = item.Key;
                }
            }
         }