实例讲解jquery与json的结合(2)

<%@ WebHandler Language="C#" %> 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; } } } }