实例讲解jquery与json的结合

时间:2020-05-14 人气:0

通过AJAX异步减少网络内容传输，而JSON则可以把传输内容缩减到纯数据；然后利用jQuery内置的AJAX功能直接获得JSON格式的数据；在客户端直接绑定到数据控件里面，从而达到最优。
1.设计htm页面

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<title>test2</title> 
<script language="javascript" type="text/javascript" src="js/jquery-latest.pack.js"></script> 
<script language="javascript" type="text/javascript" src="js/PageDate.js"></script> 
 
</head> 
<body> 
<div> 
<div> 
<br /> 
<input id="first" type="button" value=" << " /><input id="previous" type="button"
value=" < " /><input id="next" type="button" value=" > " /><input id="last" type="button"
value=" >> " /> 
 <span id="pageinfo"></span> 
<ul id="datas"> 
<li id="template"> 
<span id="OrderID"> 
订单ID 
</span>/ 
<span id="CustomerID"> 
客户ID 
</span> 
<span id="EmployeeID"> 
雇员ID 
</span>/ 
<span id="OrderDate"> 
订购日期 
</span>/ 
<span id="ShippedDate"> 
发货日期 
</span>/ 
<span id="ShippedName"> 
货主名称 
</span>/ 
<span id="ShippedAddress"> 
货主地址 
</span>/ 
<span id="ShippedCity"> 
货主城市 
</span>/ 
<span id="more"> 
更多信息 
</span> 
</li> 
</ul> 
</div> 
<div id="load" style="left: 0px; position: absolute; top: 0px; background-color: red"> 
LOADING.... 
</div> 
<input type="hidden" id="pagecount" /> 
</div> 
</body> 
</html> 
////注：ID属性比较重要，用于数据绑定。

2.使用jQuery编写AJAX请求文件

 var pageIndex = 1 
var pageCount = 0; 
 
$(function(){ 
GetPageCount();//取得分页总数 
pageCount = parseInt($("#pagecount").val());//分页总数放到变量pageCount里 
$("#load").hide();//隐藏loading提示 
$("#template").hide();//隐藏模板 
ChangeState(0,1);//设置翻页按钮的初始状态 
 
bind();//绑定第一页的数据 
 
//第一页按钮click事件 
$("#first").click(function(){ 
pageIndex = 1; 
ChangeState(0,1); 
bind(); 
}); 
 
//上一页按钮click事件 
$("#previous").click(function(){ 
pageIndex -= 1; 
ChangeState(-1,1); 
if(pageIndex <= 1) 
{ 
pageIndex = 1; 
ChangeState(0,-1); 
} 
bind(); 
}); 
 
//下一页按钮click事件 
$("#next").click(function(){ 
pageIndex += 1; 
ChangeState(1,-1); 
if(pageIndex>=pageCount) 
{ 
pageIndex = pageCount; 
ChangeState(-1,0); 
} 
bind(pageIndex); 
}); 
 
//最后一页按钮click事件 
$("#last").click(function(){ 
pageIndex = pageCount; 
ChangeState(1,0); 
bind(pageIndex); 
}); 
}); 
 
//AJAX方法取得数据并显示到页面上 
function bind() 
{ 
$("[@id=ready]").remove(); 
$("#load").show(); 
$.ajax({ 
type: "get",//使用get方法访问后台 
dataType: "json",//返回json格式的数据 
url: "Handler.ashx",//要访问的后台地址 
data: "pageIndex=" + pageIndex,//要发送的数据 
complete :function(){$("#load").hide();},//AJAX请求完成时隐藏loading提示 
success: function(msg){//msg为返回的数据，在这里做数据绑定 
var data = msg.table; 
$.each(data, function(i, n){ 
var row = $("#template").clone(); 
row.find("#OrderID").text(n.OrderID); 
row.find("#CustomerID").text(n.CustomerID); 
row.find("#EmployeeID").text(n.EmployeeID); 
row.find("#OrderDate").text(ChangeDate(n.OrderDate)); 
if(n.RequiredDate !== undefined) row.find("#ShippedDate").text(ChangeDate(n.RequiredDate)); 
row.find("#ShippedName").text(n.ShipName); 
row.find("#ShippedAddress").text(n.ShipAddress); 
row.find("#ShippedCity").text(n.ShipCity); 
row.find("#more").html("<a href=OrderInfo.aspx?id=" + n.OrderID + "&pageindex="+pageIndex+"> More</a>"); 
row.attr("id","ready");//改变绑定好数据的行的id 
row.appendTo("#datas");//添加到模板的容器中 
}); 
$("[@id=ready]").show(); 
SetPageInfo(); 
} 
}); 
} 
 
function ChangeDate(date) 
{ 
return date.replace("-","/").replace("-","/"); 
} 
 
//设置第几页/共几页的信息 
function SetPageInfo() 
{ 
$("#pageinfo").html(pageIndex + "/" + pageCount); 
} 
 
//AJAX方法取得分页总数 
function GetPageCount() 
{ 
$.ajax({ 
type: "get", 
dataType: "text", 
url: "Handler.ashx", 
data: "getPageCount=1", 
async: false, 
success: function(msg){ 
$("#pagecount").val(msg); 
} 
}); 
} 
 
//改变翻页按钮状态 
function ChangeState(state1,state2) 
{ 
if(state1 == 1) 
{ 
document.getElementById("first").disabled = ""; 
document.getElementById("previous").disabled = ""; 
} 
else if(state1 == 0) 
{ 
document.getElementById("first").disabled = "disabled"; 
document.getElementById("previous").disabled = "disabled"; 
} 
if(state2 == 1) 
{ 
document.getElementById("next").disabled = ""; 
document.getElementById("last").disabled = ""; 
} 
else if(state2 == 0) 
{ 
document.getElementById("next").disabled = "disabled"; 
document.getElementById("last").disabled = "disabled"; 
} 
}

3.利用JSON三方控件在服务器端获取JSON格式数据

<%@ WebHandler Language="C#" Class="jQueryJSON.Handler" %> 
 
using System; 
using System.Data; 
using System.Web; 
using System.Collections; 
using System.Web.Services; 
using System.Web.Services.Protocols; 
using System.Configuration; 
using System.Data.SqlClient; 
using System.Text; 
using System.Xml; 
using NetServ.Net.Json; 
 
namespace jQueryJSON 
{ 
/// <summary> 
/// $codebehindclassname$ 的摘要说明 
/// </summary> 
[WebService(Namespace = "http://tempuri.org/json/")] 
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] 
public class Handler : IHttpHandler 
{ 
readonly int PageSize = int.Parse(ConfigurationManager.AppSettings["PageSize"]); 
public void ProcessRequest(HttpContext context) 
{ 
context.Response.ContentType = "text/plain"; 
//不让浏览器缓存 
context.Response.Buffer = true; 
context.Response.ExpiresAbsolute = DateTime.Now.AddDays(-1); 
context.Response.AddHeader("pragma", "no-cache"); 
context.Response.AddHeader("cache-control", ""); 
context.Response.CacheControl = "no-cache"; 
 
string result = ""; 
if (context.Request.Params["getPageCount"] != null) result = GetPageCount(); 
if (context.Request.Params["pageIndex"] != null) 
{ 
string pageindex = context.Request.Params["pageIndex"]; 
//if (context.Cache.Get(pageindex) != null) 
// result = context.Cache.Get(pageindex).ToString(); 
//else 
//{ 
// result = GetPageData(context.Request.Params["pageIndex"]); 
// context.Cache.Add( 
// pageindex, 
// result, 
// null, 
// DateTime.Now.AddMinutes(1), 
// System.Web.Caching.Cache.NoSlidingExpiration, 
// System.Web.Caching.CacheItemPriority.Default, 
// null); 
//} 
result = GetPageData(context.Request.Params["pageIndex"]); 
} 
context.Response.Write(result); 
} 
 
private string GetPageData(string p) 
{ 
int PageIndex = int.Parse(p); 
string sql; 
if (PageIndex == 1) 
sql = "select top " + PageSize.ToString() + " * from Orders order by OrderID desc"; 
else 
sql = "select top " + PageSize.ToString() + " * from Orders where OrderID not in(select top " + ((PageIndex - 1) * PageSize).ToString() + " OrderID from Orders order by OrderID desc) order by OrderID desc"; 
string dbfile = ConfigurationManager.ConnectionStrings["conn"].ToString(); 
SqlConnection conn = new SqlConnection(dbfile); 
SqlDataAdapter da = new SqlDataAdapter(sql, conn); 
DataTable dt = new DataTable("table"); 
da.Fill(dt); 
return DataTableJson(dt); 
 
} 
 
private string GetPageCount() 
{ 
string dbfile = ConfigurationManager.ConnectionStrings["conn"].ToString(); 
SqlConnection conn = new SqlConnection(dbfile); 
SqlCommand cmd = new SqlCommand("select count(*) from Orders", conn); 
conn.Open(); 
int rowcount = Convert.ToInt32(cmd.ExecuteScalar()); 
conn.Close(); 
return ((rowcount + PageSize - 1) / PageSize).ToString(); 
} 
 
private string DataTable2Json(DataTable dt) 
{ 
StringBuilder jsonBuilder = new StringBuilder(); 
jsonBuilder.Append("{\""); 
jsonBuilder.Append(dt.TableName); 
jsonBuilder.Append("\":["); 
for (int i = 0; i < dt.Rows.Count; i++) 
{ 
jsonBuilder.Append("{"); 
for (int j = 0; j < dt.Columns.Count; j++) 
{ 
jsonBuilder.Append("\""); 
jsonBuilder.Append(dt.Columns[j].ColumnName); 
jsonBuilder.Append("\":\""); 
jsonBuilder.Append(dt.Rows[i][j].ToString()); 
jsonBuilder.Append("\","); 
} 
jsonBuilder.Remove(jsonBuilder.Length - 1, 1); 
jsonBuilder.Append("},"); 
} 
jsonBuilder.Remove(jsonBuilder.Length - 1, 1); 
jsonBuilder.Append("]"); 
jsonBuilder.Append("}"); 
return jsonBuilder.ToString(); 
} 
 
private string DataTableJson(DataTable dt) 
{ 
JsonWriter writer = new JsonWriter(); 
JsonObject content = new JsonObject(); 
JsonArray Orders = new JsonArray(); 
JsonObject Order; 
JsonObject OrderItem = new JsonObject(); 
 
for (int i = 0; i < dt.Rows.Count; i++) 
{ 
Order = new JsonObject(); 
for(int j =0;j<dt.Columns.Count;j++) 
{ 
Order.Add(dt.Columns[j].ColumnName, dt.Rows[i][j].ToString()); 
} 
Orders.Add(Order); 
} 
content.Add(dt.TableName, Orders); 
content.Write(writer); 
 
writer = new IndentedJsonWriter(); 
content.Write(writer); 
 
return writer.ToString(); 
} 
 
public bool IsReusable 
{ 
get 
{ 
return false; 
} 
} 
} 
}

以上就是jquery与json的结合实例讲解，希望对大家充分学习jquery与json的结合相关文章有所帮助。

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