实例讲解jquery与json的结合

2019-11-20 10:50:33

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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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