首先要在Web.config的<system.web>中添加下面的东东
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然后在服务器端的Page_Load中添加下面一行代码
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BigClassid 前台页面
<script type="text/javascript">
function ShowCity(id)
{
var result = chen.getCityList(id).value;
var ddlcity = document.getElementById("ddlCity");
ddlcity.length=0;
for(var i=0; i<result.Rows.length; i++)
{
ddlcity.options.add(new Option(result.Rows[i].SmallClass,result.Rows[i].id));
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<p>
省份:<asp:DropDownList ID="ddlPro" runat="server">
</asp:DropDownList>
市区:<asp:DropDownList ID="ddlCity" runat="server">
</asp:DropDownList>
</p>
<div>
</div>
</form>
</body>
<script type="text/javascript">
function ShowCity(id)
{
var result = chen.getCityList(id).value;
var ddlcity = document.getElementById("ddlCity");
ddlcity.length=0;
for(var i=0; i<result.Rows.length; i++)
{
ddlcity.options.add(new Option(result.Rows[i].SmallClass,result.Rows[i].id));
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<p>
省份:<asp:DropDownList ID="ddlPro" runat="server">
</asp:DropDownList>
市区:<asp:DropDownList ID="ddlCity" runat="server">
</asp:DropDownList>
</p>
<div>
</div>
</form>
</body>
后台:
[AjaxPro.AjaxNamespace("chen")]
public partial class ddlTwo : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
AjaxPro.Utility.RegisterTypeForAjax(typeof(ddlTwo));
SqlConnection conn = new SqlConnection("server=.; uid=sa; pwd=chen123; database=C_News; ");
conn.Open();
SqlCommand cmd = new SqlCommand("", conn);
string strsql = "select * from C_BigClass";
cmd.CommandText = strsql;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
this.ddlPro.DataSource = dt;
this.ddlPro.DataValueField = "id";
this.ddlPro.DataTextField = "BigClass";
this.ddlPro.DataBind();
this.ddlPro.Attributes["onchange"] = "ShowCity(this.options[selectedIndex].value)";
conn.Close();
}
[AjaxPro.AjaxMethod]
public DataTable getCityList(int id)
{
Hashtable ht = new Hashtable();
SqlConnection conn = new SqlConnection("server=.; uid=sa; pwd=chen123; database=C_News; ");
conn.Open();
SqlCommand cmd = new SqlCommand("", conn);
string strsql = "select * from C_SmallClass where BigClassid="+id+"";
cmd.CommandText = strsql;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
return dt;
}
}
如果我们要进行三级或四级连动,其实很简单,只要在Page_load下面this.ddlPro.Attributes["onchange"] = "ShowCity(this.options[selectedIndex].value)"; 的下面为每个下拉框都加一个方法就行了。只不过多写几个public DataTable getCityList(int id)的程序。
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