Json作為一種輕量級(jí)的數(shù)據(jù)交換格式,由于其傳輸數(shù)據(jù)格式的方便性，今天偶然想將其應(yīng)用于分頁實(shí)現(xiàn)，分頁做為web開發(fā)一個(gè)長久的話題，其應(yīng)用的高效與重要性就不多說了

本文主要技術(shù):反射機(jī)制，Json數(shù)據(jù)格式，jquery

為了應(yīng)用的通用性，首先要根據(jù)反射機(jī)制，能將要返回的任意類型的結(jié)果對象轉(zhuǎn)化成Json類型的格式。

public static String toJSON(Object obj) {

HashMap map = new HashMap();

Class c = obj.getClass();

// 利用反射機(jī) 制，把里面所有的屬性，反射出來使用，這樣放入任何一個(gè)對象， 都可以找到他們的屬性，

// 把這些屬性的名，和屬性的值，封裝成一個(gè)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對象變成字符串

// 這些格式還需要把=變成:

String s = map.toString();

/ /System.out.println(s);

String str = s.replaceAll(""=", "":");

//System.out.println(str);

return str;

}

將要返回的多個(gè)對象轉(zhuǎn)換成Json類型的對象后，最后應(yīng)加上分頁的信息，最終將多個(gè)Json字符串，轉(zhuǎn)化成一整個(gè)Json類型

{"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}

當(dāng)信息發(fā)送到客戶端時(shí) ，只用jquery接收對象的數(shù)據(jù)就行了 ，這樣 可以實(shí)現(xiàn)前臺(tái)的樣式與后臺(tái)傳送的數(shù)據(jù)分離，更加簡化了代碼

$.getJSON("result.jsp?page="+p, function(json)

{

$("#show").html("<tr><th>用戶ID</th><th>用戶名</th><th>用戶年齡</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與JSon實(shí)現(xiàn)的無刷新分頁代碼，具體代碼如下

需要四個(gè)文件

一個(gè)實(shí)體類文件 CategoryInfoModel.cs

一個(gè)SqlHelper SQLHelper.cs

一個(gè)AJAX服務(wù)端處理程序 PagedService.ashx

一個(gè)客戶端調(diào)用頁面 WSXFY.htm

CategoryInfoModel.cs和SQLHelper.cs我就不寫了，都知道是什么文件

PagedService.ashx 代碼如下

using System.Web.Script.Serialization;

public void ProcessRequest(HttpContext context)

{

context.Response.ContentType = "text/plain";

string strAction = context.Request["Action"];

//取頁數(shù)

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);

}//取每頁數(shù)據(jù)

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>();//定義實(shí)體集合

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));//序列化實(shí)體集合為javascript對象

}

}

WSXFY.htm 代碼如下

<head>

<title>無刷新分頁</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(); //不要導(dǎo)向鏈接

$.post("PagedService.ashx", { "Action": "GetPageData", "PageNum":$(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>

以上就是本文的全部內(nèi)容，希望能夠幫助大家實(shí)現(xiàn)分頁效果。