jquery+json实现分页效果

son作为一种轻量级的数据交换格式,由于其传输数据格式的方便性,今天偶然想将其应用于分页实现,分页做为web开发一个长久的话题,其应用的高效与重要性就不多说了
本文主要技术:反射机制,Json数据格式,jquery
为了应用的通用性,首先要根据反射机制,能将要返回的任意类型的结果对象转化成Json类型的格式。

public static String toJSON(Object obj) {
HashMap map = new HashMap();
Class c = obj.getClass();
// 利用反射机 制,把里面所有的属性,反射出来使用,这样放入任何一个对象, 都可以找到他们的属性,
// 把这些属性的名,和属性的值,封装成一个map里,
Field[] fields = c.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
String name = fields[i].getName();
try {
fields[i].setAccessible(true);
Object o = fields[i].get(obj);
i f (o instanceof Number) {
map.put(""" + name + """, o.toString());
} else if (o instanceof String) {
map.put(""" + name + """, """ + o.toString() + """);
}
} catch (IllegalArgumentException e) {
} catch (IllegalAccessException e) {
}
}
/ / 把map对象变成字符串
// 这些格式还需要把=变成:
String s = map.toString();
/ /System.out.println(s);
String str = s.replaceAll(""=", "":");
//System.out.println(str);
return str;
}
将要返回的多个对象转换成Json类型的对象后,最后应加上分页的信息,最终将多个Json字符串,转化成一整个Json类型
{"0":{"id":"0", "name":"dong0", "age":21},
"1":{"id":"1", "name":"dong1", "age":21},
"2":{"id":"2", "name":"dong2", "age":21},
"3":{"id":"3", "name":"dong3", "age":21},
"4":{"id":"4", "name":"dong4", "age":21},
"5":{"id":"5", "name":"dong5", "age":21},
"6":{"id":"6", "name":"dong6", "age":21},
"7":{"id":"7", "name":"dong7", "age":21},
"8":{"id":"8", "name":"dong8", "age":21},
"9":{"id":"9", "name":"dong9", "age":21},
"10":{"firstPage":1, "currentPage":1,
"default_Record_Num":10, "lastPage":10, "frontPage":1, "sum":100, "nextPage":2},
"length":11}
当信息发送到客户端时 ,只用jquery接收对象的数据就行了 ,这样 可以实现前台的样式与后台传送的数据分离,更加简化了代码
$.getJSON("result.jsp?page="+p, function(json)
{
$("#show").html("<tr><th>用户ID</th><th>用户名</th><th>用户年龄</th></tr>");
for(var i=0 ; i<json.length-1; i++){
$("#show").append("<tr><td>"+json[i]["id"]+"</td><td>"+json[i]["name"]+"</ td><td>"
+json[i]["age"]+"</td></tr>");
}
$("#currentPage").attr("value",json[json.length-1]["currentPage"]);
$("#pageCount").attr("value",json[json.length-1]["lastPage"]);
});

利用JQuery与JSon实现的无刷新分页代码,具体代码如下

需要四个文件 
一个实体类文件 CategoryInfoModel.cs 
一个SqlHelper SQLHelper.cs 
一个AJAX服务端处理程序 PagedService.ashx 
一个客户端调用页面 WSXFY.htm 
CategoryInfoModel.cs和SQLHelper.cs我就不写了,都知道是什么文件 
PagedService.ashx 代码如下

using System.Web.Script.Serialization;
public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "text/plain";
string strAction = context.Request["Action"];
//取页数
if (strAction == "GetPageCount")
{
string strSQL = "SELECT COUNT(*) FROM CategoryInfo";
int intRecordCount = SqlHelper.ExecuteScalar(strSQL);
int intPageCount = intRecordCount / 10;
if (intRecordCount % 10 != 0)
{
intPageCount++;
}
context.Response.Write(intPageCount);
}//取每页数据
else if (strAction == "GetPageData")
{
string strPageNum = context.Request["PageNum"];
int intPageNum = Convert.ToInt32(strPageNum);
int intStartRowIndex = (intPageNum - 1) * 10 + 1;
int intEndRowIndex = (intPageNum) * 10 + 1;
string strSQL = "SELECT * FROM ( SELECT ID,CategoryName,Row_Number() OVER(ORDER BY ID ASC) AS rownum FROM CategoryInfo) AS t";
strSQL += " WHERE t.rownum >= " + intStartRowIndex + " AND t.rownum <= " + intEndRowIndex;
DataSet ds = new DataSet();
SqlConnection conn = SqlHelper.GetConnection();
ds = SqlHelper.ExecuteDataset(conn, CommandType.Text, strSQL);
List<CategoryInfoModel> categoryinfo_list = new List<CategoryInfoModel>();//定义实体集合
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
CategoryInfoModel categoryinfo = new CategoryInfoModel();
categoryinfo.CategoryInfoID = Convert.ToInt32(ds.Tables[0].Rows[i]["ID"]);
categoryinfo.CategoryName = ds.Tables[0].Rows[i]["CategoryName"].ToString();
categoryinfo_list.Add(categoryinfo);
}
JavaScriptSerializer jss = new JavaScriptSerializer();
context.Response.Write(jss.Serialize(categoryinfo_list));//序列化实体集合为javascript对象
}
}
WSXFY.htm 代码如下 
<head>
<title>无刷新分页</title>
<script type="text/javascript" src="../Scripts/jquery-1.5.1.min.js"></script>
<script type="text/javascript">
$(function () {
$.post("PagedService.ashx", { "Action": "GetPageCount" }, function (response, status) {
for (var i = 1; i <= response; i++) {
var td = $("<td><a href=''>" + i + "</a></td>");
$("#trPage").append(td);
td.click(function (e) {
e.preventDefault(); //不要导向链接
$.post("PagedService.ashx", { "Action": "GetPageData", "PageNum":$(this).text() }, function (response, status) {
var categorys = $.parseJSON(response);
$("#ulCategory").empty();
for (var i = 0; i < categorys.length; i++) {
var category = categorys[i];
var li = $("<li>" + category.CategoryInfoID + "-" + category.CategoryName + "</li>");
$("#ulCategory").append(li);
}
});
});
}
});
});
</script>
</head>
<body>
<ul id="ulCategory"></ul>
<table>
<tr id="trPage">
</tr>
</table>
</body>
</html>
上一篇:WinForm GroupBox控件重绘外观


下一篇:Java的基本类型