第二节：ExtJS调用WCF系列-----分页排序列表实现

打开第一节中的那个项目，新建一个Paging.aspx的页面来实现分页列表。
这次我们使用一个测试的数据库CompanyInfoDB,里面有两张表，部门和员工，并外键关联，数据库调用采用Linq的Sqlmetal 命令方式，在Visual Studio 2008的命令提示符中输入以下命令：D:\Program Files\Microsoft Visual Studio 9.0\VC>sqlmetal /conn:server=172.16.1.52;database=CompanyInfoDB;uid=sa;pwd=sa123456 /map:c:\LinqTemp\CompanyInfoDB.map
/code:c:\LinqTemp\CompanyInfoDB.cs /serialization:Unidirectional
然后把生成的CompayInfo.map 文件和CompanyInfo.cs文件加入到项目中，并添加System.Data.Linq的引用，还要修改一下Web.Config 加入数据库链接字符串和XmlMappingSource文件的位置。
<connectionStrings>
<add name="CompanyInfoDBConnectionString" connectionString="Data Source=172.16.1.52;Initial Catalog=CompanyInfoDB;Persist Security Info=True;User ID=sa;Password=sa123456" providerName="System.Data.SqlClient"/>
</connectionStrings>
<appSettings>
<add key="CompanyInfoDBXmlMappingSource" value="E:\ExtJS\ExtJS调用WCF系列博客源文件\ExtJSAndWCFChapter1\ExtJSAndWCFChapter1\DataBase\CompanyInfoDB.map"/>
</appSettings>

如图：
为了层次更清晰一点，我们新建一个EmployeeBL.cs的类文件来处理Employee的业务逻辑，EmpployeeBL.cs的文件代码如下：

using System;

using System.Data;

using System.Configuration;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using System.Data.Linq.Mapping;

using System.IO;

using System.Linq.Dynamic;

using System.Runtime.Serialization;

namespace ExtJSAndWCFChapter1

{

public class EmployeeBL

{

CompanyInfoDB ctx;

//构造函数

public EmployeeBL()

{

XmlMappingSource xms = XmlMappingSource.FromXml(File.ReadAllText(ConfigurationManager.AppSettings["CompanyInfoDBXmlMappingSource"]));

ctx = new CompanyInfoDB(ConfigurationManager.ConnectionStrings["CompanyInfoDBConnectionString"].ConnectionString, xms);

//ctx.Log = Console.Out;

}

public string GetEmployeePaging(int start, int limit, string sort, string dir)

{

string strJsonSource = "";

var query = from emp in ctx.Employee

select new

{

EmployeeID = emp.EmployeeID,

CnName = emp.CnName,

Sex = emp.Sex,

Age = emp.Age,

Email = emp.Email,

OnWorkDate = emp.OnWorkDate,

DeptName = emp.Department.CnName

};

query = query.OrderBy(sort + " " + dir);

int TotalCount = query.Count(); //共有记录数

int PageNum = start / limit; //共有页数

int PageSize = limit; //每页记录数

query = query.Skip(PageSize * PageNum).Take(PageSize);

string JsonSource = query.ToJSON(); //当前页记录转成JSON格式

strJsonSource = @"{""TotalCount"":""" + TotalCount + "";

strJsonSource = strJsonSource + @""",""EmployeeList"":" + JsonSource + "}";

return strJsonSource;

}

这里需要两个类文件：Dynamic.cs 和 JSONHelper.cs 前者是微软提供的Linq动态查询文件，后者是scottgu的JSON序列化文件。
并在EmployeeService.svc.cs 文件中加入获取员工的分页排序方法，代码如下

/// <summary>

/// Employee分页排序

/// </summary>

/// <param name="start"></param>

/// <param name="limit"></param>

/// <param name="sort"></param>

/// <param name="dir"></param>

/// <returns></returns>

[OperationContract]

[WebInvoke(BodyStyle = WebMessageBodyStyle.Wrapped, RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, UriTemplate = "/GetEmployeePaging")]

public string GetEmployeePaging(int start, int limit, string sort, string dir)

{

if (start < 0 || sort == "") throw new ArgumentException("参数错误！");

EmployeeBL bl = new EmployeeBL();

return bl.GetEmployeePaging(start, limit, sort, dir);

}

接下来我们编写客户端代码，这次我们新建一个paging.js的文件来存放Paging.Aspx的脚本文件，ExtJS调用WCF的时候有两点须注意：
第一点：关于前一节中
[WebInvoke(BodyStyle = WebMessageBodyStyle.Bare, RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, UriTemplate = "/Get")]中的BodyStyle = WebMessageBodyStyle.Bare 和
[WebInvoke(BodyStyle = WebMessageBodyStyle.Wrapped, RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, UriTemplate = "/GetAll")]中的BodyStyle = WebMessageBodyStyle.Wrapped的区别，看前一节的两个例子，我们不难发现两个返回值的不同之处：
Get:
{"Age":28,"Birthday":"\/Date(286732800000+0800)\/","CnName":"Xiaozhuang","Email":"iamxiaozhuang@163.com","EmployeeID":"b34f963e-8520-44da-be00-bd0a1aeadc78","Sex":true}
GetAll:
{"GetAllResult":[{"Age":28,"Birthday":"\/Date(286732800000+0800)\/","CnName":"CnName","Email":"email@saf.com","EmployeeID":"2835ba7e-5f0c-41ff-8746-d6e959800850","Sex":true},{"Age":28,"Birthday":"\/Date(286732800000+0800)\/","CnName":"CnName1","Email":"email1@saf.com","EmployeeID":"d5b7a088-13a8-4195-8ce9-e0836cd33de4","Sex":false}]}
可以看到GetAll 的返回值给加了一个GetAllResult的根对象，但是这个根对象在ExtJS调用的时候是不需要的，必须去掉这个根对象才行，那么我们为什么不用WebMessageBodyStyle.Bare非要用BodyStyle = WebMessageBodyStyle.Wrapped？那是因为前者只有在WCF方法只有一个输入参数，而且不需要对其进行序列化的时候才可以使用，但是很多方法要求都不止一个参数，所以必须用后者。那我们怎样才能去掉这个根对象呢？在http://erichauser.net/?p=35有个去掉这个根对象的方法，不过他提供的那个文件有问题，不能达到预期的效果，经过调试，我把文件WCFJsonReader.js进行了改进，代码如下：

/**

* @class Ext.data.WCFJsonReader

* @extends Ext.data.JsonReader

* Custom reader for reading data from WCF. If you are using WebMessageBodyStyle.Wrapped, then WCF adds a root object to your

* JSON result:

* { "MethodResult": { "Count" : 0, "Objects": [ … ] } }

* Ext does not expect the result to have a root object before parsing, so this class will remove it.

Ext.data.WCFJsonReader = Ext.extend(Ext.data.JsonReader, {

/* @cfg {Boolean} Sets whether or not the OperationContract has the is using WebMessageBodyStyle.Wrapped */

wrapped: true,

/**

* If wrapped is set to true, we will strip WCF’s wrap object

read : function(response){

var json = response.responseText;

var o = eval("("+json+")");

if(!o) {

throw {message: "JsonReader.read: Json object not found"};

}

if (this.wrapped) {

for (var prop in o) {

if (typeof(prop) == 'string' && prop.substr(prop.length-6,prop.length) == 'Result') {

o = this.convert(o[prop]);

//o = o[prop];

break;

}

if(o.metaData){

delete this.ef;

this.meta = o.metaData;

this.recordType = Ext.data.Record.create(o.metaData.fields);

this.onMetaChange(this.meta, this.recordType, o);

}

return Ext.data.WCFJsonReader.superclass.readRecords.call(this, o);

//private

convert : function(o) {

o = eval("("+o+")");

var newResult = new Object();

for (var rootProp in o) {

newResult[rootProp] = o[rootProp];

}

return newResult;

}

});

在调用WCF的时候，用这个WCFJsonReader.js代替原始的JsonReader就可以了。
第二点：我们在调用WCF的时候要指明Content-type是application/json，而且参数必须要进行JSON序列化才可以，但是在ExtJS提供的分页排序例子中输入参数是直接由GridPanel提供的，所以我们必须截获这些参数，并对它进行JSON序列化，由此我建立了一个WCFHttpProxy.js的文件，这个文件继承自Ext.data.HttpProxy并重载了它的load方法，在这个方法里截获输入参数，并对它们进行JSON序列化。代码如下：

* Ext JS Library 2.0 RC 1

* licensing@extjs.com

* http://extjs.com/license

/**

* Author by xiaozhuang

Ext.data.WCFHttpProxy = Ext.extend(Ext.data.HttpProxy, {

load : function(params, reader, callback, scope, arg){

if(this.fireEvent("beforeload", this, params) !== false){

Ext.lib.Ajax.defaultPostHeader = 'application/json';

params = Ext.util.JSON.encode(params);

var o = {

params : params || {},

request: {

callback : callback,

scope : scope,

arg : arg

reader: reader,

callback : this.loadResponse,

scope: this

};

if(this.useAjax){

Ext.applyIf(o, this.conn);

if(this.activeRequest){

Ext.Ajax.abort(this.activeRequest);

}

this.activeRequest = Ext.Ajax.request(o);

}else{

this.conn.request(o);

}

}else{

callback.call(scope||this, null, arg, false);

}

});

其实就是增加了Ext.lib.Ajax.defaultPostHeader = 'application/json';params = Ext.util.JSON.encode(params);两行。

有了这两个文件，我们要改进一下我们的EXTJS，在它的目录下建立WCF的文件夹，并把这两个文件拷贝进去。
现在我们可以编写客户端代码了，Paging.aspx的代码如下：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Paging.aspx.cs" Inherits="ExtJSAndWCFChapter1.Paging" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>Untitled Page</title>

body .x-panel {

margin-bottom:20px;

}

.icon-grid {

background-image:url(ExtJS/icons/fam/grid.png) !important;

}

#button-grid .x-panel-body {

border:1px solid #99bbe8;

border-top:0 none;

}

.add {

background-image:url(ExtJS/icons/fam/add.gif) !important;

}

.option {

background-image:url(ExtJS/icons/fam/plugin.gif) !important;

}

.remove {

background-image:url(ExtJS/icons/fam/delete.gif) !important;

}

.save {

background-image:url(ExtJS/icons/save.gif) !important;

}

</style>

</head>

<body>

<h1>Paging Grid Example</h1><br /><br />

</form>

</body>

</html>

Paging.js的代码如下：

* Author by Xiaozhuang

Ext.onReady(function(){

// create the Data Store

var store = new Ext.data.Store({

// load using script tags for cross domain, if the data in on the same domain as

// this page, an HttpProxy would be better

proxy: new Ext.data.WCFHttpProxy({

url: '/EmployeeService.svc/GetEmployeePaging'

}),

// create reader that reads the Topic records

reader: new Ext.data.WCFJsonReader({

root: 'EmployeeList',

totalProperty: 'TotalCount',

id: 'EmployeeID',

fields: [

{name: 'EmployeeID', type: 'int'},

{name: 'CnName', type: 'string'},

{name: 'Sex', type: 'string'},

{name: 'Age', type: 'int'},

{name: 'Email', type: 'string'},

{name: 'OnWorkDate',type:'string'},

{name: 'DeptName', type: 'string'}

]

}),

// turn on remote sorting

remoteSort: true

});

store.setDefaultSort('EmployeeID', 'ASC');

// 把true和false转化为男或者女，这个其实可以在服务器端进行转化，写在这里只是为了测试

function renderSex(value, p, record){

return record.data.Sex=="true"?"男":"女";

}

//这个函数演示了怎样把服务器端的DateTime类型转为Javascript的日期

function renderOnWorkDate(value, p, record){

var jsondate = record.data.OnWorkDate;

return eval("new " + jsondate.substr(1,jsondate.length-2)).toLocaleDateString();

}

// the column model has information about grid columns

// dataIndex maps the column to the specific data field in

// the data store

var nm = new Ext.grid.RowNumberer();

var sm = new Ext.grid.CheckboxSelectionModel(); // add checkbox column

var cm = new Ext.grid.ColumnModel([nm,sm,{

header: "员工ID",

dataIndex: 'EmployeeID',

width: 100

// renderer: renderTopic

},{

header: "姓名",

dataIndex: 'CnName',

width: 200

},{

header: "性别",

dataIndex: 'Sex',

width: 70,

renderer: renderSex

},{

header: "年龄",

dataIndex: 'Age',

width: 70

},{

header: "Email",

dataIndex: 'Email',

width: 150

},{

header: "入职时间",

dataIndex: 'OnWorkDate',

width: 150,

renderer: renderOnWorkDate

},{

header: "部门",

dataIndex: 'DeptName',

width: 200

}]);

// by default columns are sortable

cm.defaultSortable = true;

var grid = new Ext.grid.GridPanel({

//el:'topic-grid',

renderTo: document.body,

width:800,

height:500,

title:'分页和排序列表',

store: store,

cm: cm,

trackMouseOver:false,

sm: sm,

loadMask: true,

viewConfig: {

forceFit:true,

enableRowBody:true,

showPreview:true,

getRowClass : function(record, rowIndex, p, store){

return 'x-grid3-row-collapsed';

}

// inline toolbars

tbar:[{

text:'添加',

tooltip:'添加一条记录',

iconCls:'add'

}, '-', {

text:'修改',

tooltip:'修改',

iconCls:'option'

},'-',{

text:'删除',

tooltip:'删除记录',

iconCls:'remove',

handler:handleDelete

}],

bbar: new Ext.PagingToolbar({

pageSize: 25,

store: store,

displayInfo: true

})

});

// render it

grid.render();

// trigger the data store load

var request={start:0,limit:25};

store.load({params:request});

function handleDelete(){

var selectedKeys = grid.selModel.selections.keys; //returns array of selected rows ids only

if(selectedKeys.length > 0)

{

Ext.MessageBox.confirm('提示','您确实要删除选定的记录吗？', deleteRecord);

}

else

{

Ext.MessageBox.alert('提示','请至少选择一条记录！');

}//end

}

function deleteRecord(btn){

if(btn=='yes'){

store.reload();

}//end if click 'yes' on button

} // end deleteRecord

});

运行结果：

源代码下载在这里

posted on 2007-12-11 10:17 小庄阅读(8585) 评论(12) 编辑收藏举报