jquery+json implement paging effect

Json as a lightweight data interchange format, due to the convenience of its transmission of data format, today I happen to want to use it in the implementation of paging, paging as web development a long-term topic, its application efficiency and importance is not much said
The main techniques in this paper: reflection mechanism, Json data format, jquery
For versatility, the first step is to convert any type of result object that is to be returned to an Json format based on the reflection mechanism.

public static String toJSON(Object obj) {
HashMap map = new HashMap();
Class c = obj.getClass();
//  Use reflector   System, all the inside of the properties, reflected to use, so into any 1 An object,   You can find their properties, 
//  Encapsulate the names of these properties and the values of these properties as 1 a map In, 
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) {
}
}
/ /  the map Object becomes a string 
//  These formats still need to be put together = become :
String s = map.toString();
/ /System.out.println(s);
String str = s.replaceAll(""=", "":");
//System.out.println(str);
return str;
}

After the multiple objects to be returned are converted to Json objects, the paging information should be added at the end to convert the multiple Json strings to the entire Json type

{"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}

When the information is sent to the client, only jquery receives the object's data on the line, which can achieve the foreground style and the background transmission of data separation, more simplified code

$.getJSON("result.jsp?page="+p, function(json)
{
$("#show").html("<tr><th> The user ID</th><th> The user name </th><th> The user's age </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"]);
});

Using JQuery and JSon to achieve no refresh paging code, the specific code is as follows

Four files are required
1 entity class file CategoryInfoModel.cs
1 SqlHelper SQLHelper cs
1 AJAX server handler PagedService.ashx
1 client invocation page WSXFY.htm
CategoryInfoModel.cs and SQLHelper.cs, I won't write them down, do you know what they are
PagedService. The ashx code is as follows

using System.Web.Script.Serialization; 
public void ProcessRequest(HttpContext context) 
{ 
context.Response.ContentType = "text/plain"; 
string strAction = context.Request["Action"]; 
// Take pages  
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); 
}// Fetch each page of data  
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>();// Defining a collection of entities  
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));// The serialized entity collection is javascript object  
} 
} 

WSXFY. The htm code is as follows

<head> 
<title> No flush pages </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(); // Don't lead to links  
$.post("PagedService.ashx", { "Action": "GetPageData", "PageNum":$(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> 

That's the end of this article, hopefully to help you achieve pagination.