Exemples pour expliquer la combinaison de jquery et json

Réduisez la transmission du contenu du réseau de manière asynchrone via AJAX, tandis que JSON peut réduire le contenu de la transmission à des données pures ; puis utilisez la fonction AJAX intégrée de jQuery pour obtenir directement les données au format JSON ; atteindre l’Optimal.
1. Concevoir une page htm

<!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。

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2. Utilisez jQuery pour écrire des fichiers de requête AJAX

 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&#63;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"; 
} 
}

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3. Utilisez les contrôles tiers JSON pour obtenir des données au format JSON côté serveur

<%@ 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; 
} 
} 
} 
}

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Exemples pour expliquer la combinaison de jquery et json_jquery