使用jQuery+HttpHandler+xml模拟一个三级联动的例子_jquery

public class Province
{
private string id;
///

/// 编号
///

public string Id
{
get { return id; }
set { id = value; }
}
private string name;
///

/// 名称
///

public string Name
{
get { return name; }
set { name = value; }
}
}

public class City
{
private string id;
///

/// 编号
///

public string Id
{
get { return id; }
set { id = value; }
}
private string name;
///

/// 名称
///

public string Name
{
get { return name; }
set { name = value; }
}
}

public class County
{
private string id;
///

/// 编号
///

public string Id
{
get { return id; }
set { id = value; }
}
private string name;
///

/// 名称
///

public string Name
{
get { return name; }
set { name = value; }
}
}

///

2 /// 处理程序
3 ///

4 public class Handler : IHttpHandler
5 {
6
7 private static XDocument doc;
8 private string filePath = HttpContext.Current.Server.MapPath("~/Area.xml");
9 //javascript序列化类
private static JavaScriptSerializer jss = new JavaScriptSerializer();
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string result = "failure";//默认返回结果为失败
HttpRequest req = context.Request;
string province = req["province"];//获取用户选择的省的编号
string city = req["city"];//获取用户选择的市的编号
string county = req["county"];//获取用户选择的县的编号
string type = req["type"];//获取用户需要获取的省市县列表的类型
InitDoc();
if (type.HasValue())
{
switch (type.ToLower())
{
case "province"://如果用户需要获取省级列表
result = jss.Serialize(GetProvinceList());
break;
case "city"://如果用户需要获取的是市级列表
result = jss.Serialize(GetCityListByProvince(province));
break;
case "county"://如果用户需要获取的是县级列表
result = jss.Serialize(GetCountyListByCity(province, city));
break;
default:
break;
}
}
//将结果以文本的格式返回给客户端
context.Response.Write(result);
}
///

/// 初始化文档对象
///

private void InitDoc()
{
if (doc == null)
{
doc = XDocument.Load(filePath);
}
}
///

/// 初始化省级列表
///

private List GetProvinceList()
{
List list = new List();
if (doc != null)
{
XElement root = doc.Root;
foreach (var prov in root.XPathSelectElements("province"))
{
list.Add(new Province()
{
Id = prov.Attribute("id").Value,
Name = prov.Attribute("name").Value
});
}
}
return list;
}
///

/// 根据省级编号获取市级编号
///

/// 省级编号
private List GetCityListByProvince(string provId)
{
List list = new List();
if (doc != null)
{
XElement root = doc.Root;
//xpath表达式：/area/province[@id='1']/city
string queryPath = "/area/province[@id='" + provId + "']/city";
foreach (var city in root.XPathSelectElements(queryPath))
{
list.Add(new City()
{
Id = city.Attribute("id").Value,
Name = city.Attribute("name").Value
});
}
}
return list;
}
///

/// 根据省级编号和市级编号获取县级编号
///

/// 省级编号
/// 市级编号
private List GetCountyListByCity(string provId, string cityId)
{
List list = new List();
if (doc != null)
{
XElement root = doc.Root;
string queryPath = "/area/province[@id='" + provId + "']/city[@id='" + cityId + "']/county";
foreach (var county in root.XPathSelectElements(queryPath))
{
list.Add(new County()
{
Id = county.Attribute("id").Value,
Name = county.Attribute("name").Value
});
}
}
return list;
}
public bool IsReusable
{
get
{
return false;
}
}
}

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