添加引用：http://www.webxml.com.cn/WebServices/WeatherWebService.asmx
.cs代码：
WeatherWebServiceSoap w = new WeatherWebServiceSoapClient("WeatherWebServiceSoap");
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindPro();
BindCity();
}
}
//province
protected void BindPro()
{
string[] pro = w.getSupportProvince();
for (int i = 0; i < pro.Length; i++)
{
ddlProv.Items.Add(new ListItem(pro[i],pro[i]));
}
}
//city
protected void BindCity()
{
ddlCity.Items.Clear();
string[] city = w.getSupportCity(ddlProv.SelectedValue);
for (int i = 0; i < city.Length; i++)
{
ddlCity.Items.Add(new ListItem(city[i],city[i]));
}
}
//weather
protected void BindWeather()
{
string city = ddlCity.SelectedValue.ToString().Substring(0,2);
//Response.Write(city);
string[] mystr = w.getWeatherbyCityName(city);
//for (int i = 0; i < mystr.Length; i++)
//{
// Response.Write(mystr[8]+"<br/>");
//img.ImageUrl = "images/a_" + mystr[8];
//}
//mystr[0] 省
//mystr[2] 城市后的代码
labCity.Text = mystr[1];//城市
Label2.Text = mystr[6];//日期+天气情况（如：7月4日 多云）
Label3.Text = mystr[5];//温度（如：28℃/34℃）
Label4.Text = mystr[4];//时间（如：2012-7-4 12:04:38）
}
protected void ddlProv_SelectedIndexChanged(object sender, EventArgs e)
{
BindCity();
}
protected void Button1_Click(object sender, EventArgs e)
{
BindWeather();
}
html代码：
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList ID="ddlProv" runat="server" AutoPostBack="True" onselectedindexchanged="ddlProv_SelectedIndexChanged"></asp:DropDownList>
<asp:DropDownList ID="ddlCity" runat="server"></asp:DropDownList>
<asp:Label ID="labCity" runat="server" Text="Label"></asp:Label>
<asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
<asp:Label ID="Label3" runat="server" Text="Label"></asp:Label>
<asp:Label ID="Label4" runat="server" Text="Label"></asp:Label>
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="获 取" />
</div>
</form>
</body>
