JQuery AJAX & JSON 使用示例一步到位（DEMO：ASP.NET + MSSQL 无限级树形菜单）

最新推荐文章于 2021-02-16 03:06:37 发布

原创最新推荐文章于 2021-02-16 03:06:37 发布 · 5.5k 阅读

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#json #asp.net #jquery #ajax #string #dataset

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本文介绍了一种使用ASP.NET结合JavaScript技术实现的无限级树型菜单的方法。该方案通过Ajax从服务器获取数据，利用jQuery处理JSON格式的数据，并通过递归的方式构建出树形结构的菜单。

部署运行你感兴趣的模型镜像

文中使用的JS树形菜单函数参照：

ASP.NET JS+Sql无限级树型菜单

功能说明：

由Tree.html中的JQuery AJAX代码发起HTTP请求到GetTreeData.aspx获取JSON格式的字符串，然后在Tree.html中将字符串格式化为JSON格式，用dTree函数递归构造JS Tree。

步骤：

1）创建Menu类（为了构造List<T>泛型集合）

2）创建FormatToJson类

3）创建GetTreeData.aspx窗体，添加后台实现代码

4）创建Tree.html，并处理数据递归绑定Tree

1、Tree.html

<!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></title> <mce:script type="text/javascript" src="Scripts/dtree.js" mce_src="Scripts/dtree.js"></mce:script> <mce:script type="text/javascript" src="Scripts/jquery-1.4.1.js" mce_src="Scripts/jquery-1.4.1.js"></mce:script> <mce:script type="text/javascript"></mce:script> <mce:style type="text/css"></mce:style><style type="text/css" mce_bogus="1"> img { border:0px; } </style> </head> <body>  <img id="imgLoading" src="Images/Loading/loading01.gif" mce_src="Images/Loading/loading01.gif" alt="正在加载..." />  <div id="divTree"> </div> </body> </html>

2、请求数据的ASP.NET网页后台代码（前台清空就剩Page命令那一行就可以了）

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using DAO; using System.Data; using System.Text; using System.Reflection; public partial class TreeSource_GetTreeData : System.Web.UI.Page { SqlHelper helper = new SqlHelper(); protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { this.GetMenuByParentID(); } } private void GetMenuByParentID() { if (ParentID != null) { DataTable dt = helper.FillDataTable(String.Format( "SELECT * FROM SunZonTMSMenu WHERE ParentMenuID={0} AND IsOpen=1", ParentID.ToString() )); IList<Menu> menu = new List<Menu>(); if (dt != null && dt.Rows.Count > 0) { foreach (DataRow dr in dt.Rows) { menu.Add(new Menu() { ID=Int32.Parse(dr["ID"].ToString()), ParentMenuID = Int32.Parse(dr["ParentMenuID"].ToString()), MenuName = dr["MenuName"].ToString(), MenuCode = dr["MenuCode"].ToString(), MenuClickURL = dr["MenuClickURL"].ToString() }); } } if (menu.Count > 0) { Response.Write(FormatToJson.ListToJson<Menu>(menu)); } } } //上级Menu的ID private Int32? ParentID { get { try { return Int32.Parse(Request.QueryString["parentID"]); } catch { return null; } } } }

3、使用到的Menu实体类

using System; using System.Collections.Generic; using System.Linq; using System.Web; /// <summary> /// Summary description for Menu /// </summary> public class Menu { public Menu() { // // TODO: Add constructor logic here // } public int ID { get; set; } public int ParentMenuID { get; set; } public string MenuName { get; set; } public string MenuCode { get; set; } public string MenuClickURL { get; set; } }

4、使用的构造JSON数据格式的类（此类不是本人写的，来源于互联网）

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Text; using System.Reflection; using System.Collections; using System.Data; using System.Data.Common; /// <summary> /// Summary description for FormatToJson /// </summary> public class FormatToJson { public FormatToJson() { // // TODO: Add constructor logic here // } /// <summary> /// List转成json /// </summary> /// <typeparam name="T"></typeparam> /// <param name="jsonName"></param> /// <param name="list"></param> /// <returns></returns> public static string ListToJson<T>(IList<T> list, string jsonName) { StringBuilder Json = new StringBuilder(); if (string.IsNullOrEmpty(jsonName)) jsonName = list[0].GetType().Name; Json.Append("{/"" + jsonName + "/":["); if (list.Count > 0) { for (int i = 0; i < list.Count; i++) { T obj = Activator.CreateInstance<T>(); PropertyInfo[] pi = obj.GetType().GetProperties(); Json.Append("{"); for (int j = 0; j < pi.Length; j++) { Type type = pi[j].GetValue(list[i], null).GetType(); Json.Append("/"" + pi[j].Name.ToString() + "/":" + StringFormat(pi[j].GetValue(list[i], null).ToString(), type)); if (j < pi.Length - 1) { Json.Append(","); } } Json.Append("}"); if (i < list.Count - 1) { Json.Append(","); } } } Json.Append("]}"); return Json.ToString(); } /// <summary> /// List转成json /// </summary> /// <typeparam name="T"></typeparam> /// <param name="list"></param> /// <returns></returns> public static string ListToJson<T>(IList<T> list) { object obj = list[0]; return ListToJson<T>(list, obj.GetType().Name); } /// <summary> /// 对象转换为Json字符串 /// </summary> /// <param name="jsonObject">对象</param> /// <returns>Json字符串</returns> public static string ToJson(object jsonObject) { string jsonString = "{"; PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties(); for (int i = 0; i < propertyInfo.Length; i++) { object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject, null); string value = string.Empty; if (objectValue is DateTime || objectValue is Guid || objectValue is TimeSpan) { value = "'" + objectValue.ToString() + "'"; } else if (objectValue is string) { value = "'" + ToJson(objectValue.ToString()) + "'"; } else if (objectValue is IEnumerable) { value = ToJson((IEnumerable)objectValue); } else { value = ToJson(objectValue.ToString()); } jsonString += "/"" + ToJson(propertyInfo[i].Name) + "/":" + value + ","; } jsonString.Remove(jsonString.Length - 1, jsonString.Length); return jsonString + "}"; } /// <summary> /// 对象集合转换Json /// </summary> /// <param name="array">集合对象</param> /// <returns>Json字符串</returns> public static string ToJson(IEnumerable array) { string jsonString = "["; foreach (object item in array) { jsonString += ToJson(item) + ","; } jsonString.Remove(jsonString.Length - 1, jsonString.Length); return jsonString + "]"; } /// <summary> /// 普通集合转换Json /// </summary> /// <param name="array">集合对象</param> /// <returns>Json字符串</returns> public static string ToArrayString(IEnumerable array) { string jsonString = "["; foreach (object item in array) { jsonString = ToJson(item.ToString()) + ","; } jsonString.Remove(jsonString.Length - 1, jsonString.Length); return jsonString + "]"; } /// <summary> /// Datatable转换为Json /// </summary> /// <param name="table">Datatable对象</param> /// <returns>Json字符串</returns> public static string ToJson(DataTable dt) { StringBuilder jsonString = new StringBuilder(); jsonString.Append("["); DataRowCollection drc = dt.Rows; for (int i = 0; i < drc.Count; i++) { jsonString.Append("{"); for (int j = 0; j < dt.Columns.Count; j++) { string strKey = dt.Columns[j].ColumnName; string strValue = drc[i][j].ToString(); Type type = dt.Columns[j].DataType; jsonString.Append("/"" + strKey + "/":"); strValue = StringFormat(strValue, type); if (j < dt.Columns.Count - 1) { jsonString.Append(strValue + ","); } else { jsonString.Append(strValue); } } jsonString.Append("},"); } jsonString.Remove(jsonString.Length - 1, 1); jsonString.Append("]"); return jsonString.ToString(); } /// <summary> /// DataTable转成Json /// </summary> /// <param name="jsonName"></param> /// <param name="dt"></param> /// <returns></returns> public static string ToJson(DataTable dt, string jsonName) { StringBuilder Json = new StringBuilder(); if (string.IsNullOrEmpty(jsonName)) jsonName = dt.TableName; Json.Append("{/"" + jsonName + "/":["); if (dt.Rows.Count > 0) { for (int i = 0; i < dt.Rows.Count; i++) { Json.Append("{"); for (int j = 0; j < dt.Columns.Count; j++) { Type type = dt.Rows[i][j].GetType(); Json.Append("/"" + dt.Columns[j].ColumnName.ToString() + "/":" + StringFormat(dt.Rows[i][j].ToString(), type)); if (j < dt.Columns.Count - 1) { Json.Append(","); } } Json.Append("}"); if (i < dt.Rows.Count - 1) { Json.Append(","); } } } Json.Append("]}"); return Json.ToString(); } /// <summary> /// DataReader转换为Json /// </summary> /// <param name="dataReader">DataReader对象</param> /// <returns>Json字符串</returns> public static string ToJson(DbDataReader dataReader) { StringBuilder jsonString = new StringBuilder(); jsonString.Append("["); while (dataReader.Read()) { jsonString.Append("{"); for (int i = 0; i < dataReader.FieldCount; i++) { Type type = dataReader.GetFieldType(i); string strKey = dataReader.GetName(i); string strValue = dataReader[i].ToString(); jsonString.Append("/"" + strKey + "/":"); strValue = StringFormat(strValue, type); if (i < dataReader.FieldCount - 1) { jsonString.Append(strValue + ","); } else { jsonString.Append(strValue); } } jsonString.Append("},"); } dataReader.Close(); jsonString.Remove(jsonString.Length - 1, 1); jsonString.Append("]"); return jsonString.ToString(); } /// <summary> /// DataSet转换为Json /// </summary> /// <param name="dataSet">DataSet对象</param> /// <returns>Json字符串</returns> public static string ToJson(DataSet dataSet) { string jsonString = "{"; foreach (DataTable table in dataSet.Tables) { jsonString += "/"" + table.TableName + "/":" + ToJson(table) + ","; } jsonString = jsonString.TrimEnd(','); return jsonString + "}"; } /// <summary> /// 过滤特殊字符 /// </summary> /// <param name="s"></param> /// <returns></returns> private static string String2Json(String s) { StringBuilder sb = new StringBuilder(); for (int i = 0; i < s.Length; i++) { char c = s.ToCharArray()[i]; switch (c) { case '/"': sb.Append("///""); break; case '//': sb.Append("////"); break; case '/': sb.Append("///"); break; case '/b': sb.Append("//b"); break; case '/f': sb.Append("//f"); break; case '/n': sb.Append("//n"); break; case '/r': sb.Append("//r"); break; case '/t': sb.Append("//t"); break; default: sb.Append(c); break; } } return sb.ToString(); } /// <summary> /// 格式化字符型、日期型、布尔型 /// </summary> /// <param name="str"></param> /// <param name="type"></param> /// <returns></returns> private static string StringFormat(string str, Type type) { if (type == typeof(string)) { str = String2Json(str); str = "/"" + str + "/""; } else if (type == typeof(DateTime)) { str = "/"" + str + "/""; } else if (type == typeof(bool)) { str = str.ToLower(); } return str; } }

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