动态添加下更多拉框 添加下拉框的内容从数据库读取内容

[moonwrite]

第一个下拉框选择内容

如果数据库中还有它的子类的话
就添加多一个下拉框 显示它的子类选项

如果选择生成的下拉框选择的内容又有子类的话
有动态添加一个下拉框 显示它的子类选择

一直... ...

[moudy]

如果级数不限定，个人认为用树控件更好。不然下拉框位置控制也麻烦，每次刷新时还要根据当前显示的内容再次动态生成控件，多麻烦。

[C5662601]

PlaceHolder

[C5662601]

private void createdrop()
		{
			int i = 0;
			int k = 0;
			DataSet ds = (DataSet)ViewState["DS"];
			if(ViewState["PlaceHoldernum"] != null)
			{
				i = Convert.ToInt32(ViewState["PlaceHoldernum"].ToString());
				for(; k < i; k++)
				{
					DropDownList tmp = new DropDownList();
					tmp.ID = "drop" + k.ToString();
					switch(k % 5) 
					{
						case 0:
							utility.Method.BindList(tmp,ds.Tables[8],"");//身份类别
							break;
						case 1:
							utility.Method.BindList(tmp,ds.Tables[2],"");//学制
							break;
						case 2:
							utility.Method.BindList(tmp,ds.Tables[3]);//科别
							break;
						case 3:
							utility.Method.BindList(tmp,ds.Tables[4]);//年级
							break;
						case 4:
							utility.Method.BindList(tmp,ds.Tables[5]);//班别
							break;
						default:
							break;
					}
					PlaceHolder2.Controls.Add(tmp);
					if((k+1) % 5 == 0)
						PlaceHolder2.Controls.Add(new HtmlGenericControl("br"));
				}
			}
		}

[C5662601]

private void Button3_Click(object sender, System.EventArgs e)
{
int k = Convert.ToInt32(ViewState["PlaceHoldernum"]);
DataSet ds = (DataSet)ViewState["DS"];
DropDownList drop1 = new DropDownList();
drop1.ID = "drop" + k.ToString();
utility.Method.BindList(drop1,ds.Tables[8],"");//身份类别
PlaceHolder2.Controls.Add(drop1);
k++;
DropDownList drop2 = new DropDownList();
drop2.ID = "drop" + k.ToString();
utility.Method.BindList(drop2,ds.Tables[2],"");//学制
PlaceHolder2.Controls.Add(drop2);
k++;
DropDownList drop3 = new DropDownList();
drop3.ID = "drop" + k.ToString();
utility.Method.BindList(drop3,ds.Tables[3]);//科别
PlaceHolder2.Controls.Add(drop3);
k++;
DropDownList drop4 = new DropDownList();
drop4.ID = "drop" + k.ToString();
utility.Method.BindList(drop4,ds.Tables[4]);//年级
PlaceHolder2.Controls.Add(drop4);
k++;
DropDownList drop5 = new DropDownList();
drop5.ID = "drop" + k.ToString();
utility.Method.BindList(drop5,ds.Tables[5]);//班别
PlaceHolder2.Controls.Add(drop5);
k++;
PlaceHolder2.Controls.Add(new HtmlGenericControl("br"));
ViewState["PlaceHoldernum"] = k;
}

[criedshy]

为什么不用树型控件？

[kelerqd]

建议用Ajax 可满足动态添加！

[moonwrite]

可能是我的表达有不明确

如：http://search1.taobao.com/browse/ad_search.htm 的 类别

只是可能下拉框更多

[flyerwing]

webform:
dropdownlist1.datasource=datatable;
dropdownlist1.text="name";
dropdownlist1.value="id";
dropdownlist1.dataBind();
<select id="sl">
<%for(int i=0;i<dt.rows.cout;++i)%>
<option value="<%=dt.rows[i]["id"].ToString()%>"><%=dt.rows[i]["name"].ToString()%></option>
</select>
............
winform:
combox1.datasource=dt;
combox1.displaymember="name";
combox1.valuemember="id";
.....