Flex4之DataGrid示例【客户端和服务器端]
由于我的DataGrid与JAVA后台交互需要返回JSON格式的字符串，所以需要在客户端来解析JSON串，用到JSON相关类，所以Flex4还缺少一个文件corelib.swc
将corelib.swc拷贝到Flex安装目录的sdks\4.0.0\frameworks\libs下
这个文件导入后重启MyEclipse就可以使用JSON类了
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1，客户端、服务端
（1）客户端分页：将数据一次性取到客户端，客户要看哪一页的数据，显示哪一页的数据。
（2）服务端分页：客户要看哪一页的数据，向服务端请求哪一页的数据，客户端将请求到的数据显示给用户（可以在客户端、服务端分别做缓存，加快数据的读取），由于flex本身不具有数据库访问能力，可以考虑通过 WebServices向服务器传递数据，数据的表示形式可以是XML、JSON（本文采用XML的形式）
2，分页表示层的设计
（1）页码条中4个按钮；这四个按钮分别为转到第一页，前一页，后一页，最后一页；当这四个按钮中的任意一点被点击时，页码要重绘，当前页码变化；且还要考虑当页码中有第一页时，前两个按钮要隐藏起来；当页码中有最后一页时，后两个按钮要隐藏起来。
（2）页码条中页码；当点击页码条中的页码时，DataGrid中更新显示数据即可，当前页码变化。
（3）显示总页数，总记录数；
（4）每页记录数，让用户通过下拉框选择；当用户选择新的每页显示记录数时，页码要重绘，总页数发生变化，当前页码变化。
（5）页码输入框，让用户输入任意页码（要检查输入数据是否合法），DataGrid显示页码中的数据，页码要重绘，总页数变化。
（6）查看所有；分页中的特殊情况，将每页记数置为记录总数即可达到要求！页码要重绘，总页数发生变化，当前页码变化
代码说明
（1）分页功能条，做一个自定义组件
（2）页码条绘制方法，传参数为页码中的第一个页码
3.分页触发的方法，组件中有一个属性为pagingFunction，为向服务端请求数据的函数；当该函数为空时，调用客户端分页；反之调用该方法进行服务端分页。
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首先说明下：以下的四个例子中每一个都含有客户端获取DataGrid数据的代码
下面的每个mxml中都涉及用到的组件mxml,位于com/control目录下
<?xml version="1.0" encoding="utf-8"?><s:HGroup xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300"><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 --></fx:Declarations><fx:Script><![CDATA[import mx.collections.ArrayCollection; import mx.events.ItemClickEvent; import flash.events.KeyboardEvent; import mx.controls.DataGrid; import mx.validators.NumberValidator; [Bindable] /* [Embed(source='assets/first.gif',mimeType='image/gif')] */private var firstIcon:Class; private var firstPage:uint; [Bindable] /* [Embed(source='assets/pre.gif',mimeType='image/gif')] */private var preIcon:Class; private var prePage:uint; [Bindable] /* [Embed(source='assets/next.gif',mimeType='image/gif')] */private var nextIcon:Class; private var nextPage:uint; [Bindable] /* [Embed(source='assets/last.gif',mimeType='image/gif')] */private var lastIcon:Class; private var lastPage:uint; //页码条数据,绑定 [Bindable] private var nav:ArrayCollection = new ArrayCollection(); //默认起始页码,第1页 private var currentPageIndex:uint = 0; //是否已初始化 private var isInit:Boolean=true; //总页数 private var totalPages:uint = 0; //是否重绘页码条，当使用服务端分页时使用 private var isCreateNavBar:Boolean = true; /************************************************************/ //显示到Grid的数据 [Bindable] public var viewData:ArrayCollection=null; //所有的数据 public var orgData:ArrayCollection=null; //每页记录数下拉框 public var pageSizeDropDownListData:ArrayCollection=null; // 每页记录数 public var pageSize:uint = 5; // 页码条上显示页码的个数 public var navSize:uint = 5; //记录总数，调用服务端发页时使用 public var totalRecord:int=0; //分页函数 public var pagingFunction:Function=null; //分页条对应的Grid public var dataGrid:DataGrid=null; /***************************************************************/ public function dataBind(isServerSide:Boolean=false):void{ //是否初始化 if(isInit){ if(pageSizeDropDownListData==null){ pageSizeDropDownListData = new ArrayCollection(); pageSizeDropDownListData.addItem({label:5,data:5}); pageSizeDropDownListData.addItem({label:10,data:10}); pageSizeDropDownListData.addItem({label:20,data:20}); pageSizeDropDownListData.addItem({label:30,data:30}); } pageSizeComobox.dataProvider=pageSizeDropDownListData; isInit=false; } // refreshDataProvider(currentPageIndex,isCreateNavBar,pageSize,isServerSide); } /** * 构建页码条 * pages:总页数 * pageIndex:当前页（注意，从0开始） * */ private function createNavBar(pageIndex:uint = 0):void{ nav.removeAll(); //向前图标操作,first,Pre if( pageIndex > 1 ){ firstPage=0; firstNavBtn.visible=true; // var intLFive:int = pageIndex-navSize; // calculate start of last 5; // prePage=intLFive; preNavBtn.visible=true; } else{ firstNavBtn.visible=false; preNavBtn.visible=false; } //页码条 for( var x:uint = 0; x < navSize; x++){ var pg:uint = x + pageIndex; nav.addItem({label: pg + 1,data: pg}); // var pgg:uint = pg+1; if(pgg>=totalPages){ //搜索到最后一个页码，停止添加到navbar x=navSize; } } //计算最后一组页码条中第一个页码的页码编号 var lastpage:Number = 0; for( var y:uint = navSize; y <= totalPages-1;y = y + navSize ){ //lets calculate the lastpage button if(y+5 > navSize){ lastpage = y; } } //向后图标 if( pg < totalPages - 1 ){ nextPage=pg + 1; nextNavBtn.visible=true; lastPage=lastpage; lastNavBtn.visible=true; } else{ nextNavBtn.visible=false; lastNavBtn.visible=false; } } /** * 页码按钮按下(页码条点击) */ private function navigatePage(event:ItemClickEvent):void { refreshDataProvider(event.item.data,false); } /** * 页码按钮按下,first,pre,next,last */ private function navigateButtonClick(pageString:String):void{ var pageIndex:uint=0; switch(pageString){ case "firstPage": pageIndex=firstPage; break; case "prePage": pageIndex=prePage; break; case "nextPage": pageIndex=nextPage; break; default: //lastPage pageIndex=lastPage; } // refreshDataProvider(pageIndex); } /** * 更新数据源,更新表格显示数据 */ private function refreshDataProvider(pageIndex:uint,isCreateNavBar:Boolean=true,pageSize:uint=0,resultReturn:Boolean=false):void{ //分页函数 if(dataGrid==null) return; currentPageIndex=pageIndex; if(pageSize==0){ pageSize=this.pageSize; }else{ this.pageSize=pageSize; if(!resultReturn) totalPages = Math.ceil(orgData.length/pageSize); } if(!resultReturn){ if(this.pagingFunction!=null){ pagingFunction(pageIndex,pageSize); this.isCreateNavBar=isCreateNavBar; } else{ viewData = new ArrayCollection( orgData.source.slice((pageIndex * pageSize),(pageIndex * pageSize) + pageSize) ); dataGrid.dataProvider=viewData; pageNumber.text=(pageIndex+1).toString(); totalRecordLabel.text = '总记录数：' + orgData.length.toString(); } } else{ dataGrid.dataProvider=orgData; totalPages = Math.ceil(totalRecord/pageSize); pageNumber.text=(pageIndex+1).toString(); totalRecordLabel.text = '总记录数：' + totalRecord.toString() } totalPagesLabel.text = '总页数：' + totalPages; if(isCreateNavBar) createNavBar(pageIndex); } // /** * 每页记录数变更（下拉框选择） */ private function pageSizeSelectChange():void{ refreshDataProvider(0,true,uint(pageSizeComobox.value)); } /** * 页码变更（直接输入） */ private function pageIndexInsertChange(event:Event):void{ var keyboardEvent:KeyboardEvent=event as KeyboardEvent; if(keyboardEvent!=null&&keyboardEvent.keyCode== Keyboard.ENTER){ var pageIndex:uint=uint(pageNumber.text)-1; if(pageIndex>0&&pageIndex<totalPages&&pageIndex!=currentPageIndex){ refreshDataProvider(pageIndex); } else{ pageNumber.text = (currentPageIndex+1).toString(); } } } /** * 查看所有 */ private function viewAll():void{ var tempTotalRecord:uint=0; if(pagingFunction!=null) tempTotalRecord=totalRecord; else tempTotalRecord=orgData.length; // pageSizeComobox.text=tempTotalRecord.toString(); pageSizeComobox.selectedIndex=-1; refreshDataProvider(0,true,tempTotalRecord); }]]></fx:Script><mx:HBox paddingTop="8"> <mx:Button id="firstNavBtn" icon="{firstIcon}" width="10" height="10" click="navigateButtonClick('firstPage');" /> <mx:Button id="preNavBtn" icon="{preIcon}" width="7" height="10" click="navigateButtonClick('prePage');"/> </mx:HBox> <mx:LinkBar id="pageNav" itemClick="navigatePage(event)" dataProvider="{nav}"/> <mx:HBox paddingTop="8"> <mx:Button id="nextNavBtn" icon="{nextIcon}" width="7" height="10" click="navigateButtonClick('nextPage');"/> <mx:Button id="lastNavBtn" icon="{lastIcon}" width="10" height="10" click="navigateButtonClick('lastPage');"/> </mx:HBox> <mx:VRule height="25"/> <mx:Label paddingTop="3" id="totalPagesLabel" text=""/> <mx:Label paddingTop="3" id="totalRecordLabel" text=""/> <mx:Label paddingTop="3" text="每页记录:"/> <mx:ComboBox id="pageSizeComobox" cornerRadius="0" paddingLeft="0" fontWeight="normal" width="50" arrowButtonWidth="10" change="pageSizeSelectChange()"/> <mx:Label paddingTop="3" text="页码:"/> <mx:TextInput id="pageNumber" width="40" keyDown="pageIndexInsertChange(event);"/> <mx:LinkButton id="viewAllLinkBtn" label="查看所有" click="viewAll();"/> </s:HGroup>?第一：??HTTPService获取服务器端数据显示DataGrid
<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx" xmlns:control="com.control.*" creationComplete="creationCompleteHandle();myservice.send()" minWidth="955" minHeight="900" width="1000" height="900"><fx:Style>Application{fontSize:12;}</fx:Style><fx:Declarations><!-- 将非可视元素（例如服务、值对象）放在此处 这个HTTPService使用时一定要提前调用send方法--><s:HTTPService id="myservice" url="http://localhost/Flex_04_DataGird_Paging/servlet/FindDataServlet" result="myservice_resultHandler(event)" /></fx:Declarations><fx:Script><![CDATA[import com.adobe.serialization.json.JSON;import mx.collections.ArrayCollection;import mx.controls.Alert;import mx.rpc.events.FaultEvent;import mx.rpc.events.ResultEvent;private var pageIndex:int=0;private var pageSize:int=5;private function creationCompleteHandle():void{var orgData:ArrayCollection = new ArrayCollection();for( var x:uint = 1; x <= 555; x++ ){var obj:Object = new Object();obj.ID = "id " + x.toString();obj.Code="order "+x;obj.Total=x*1000;obj.Customer= "customer "+x;obj.Register = "employee";obj.Memo="memo "+x; obj.State="auditing state"; orgData.addItem(obj);}clientPagingBar1.dataGrid=DataGrid1;clientPagingBar1.orgData=orgData;clientPagingBar1.dataBind();}protected function myservice_resultHandler(event:ResultEvent):void{var rawData:String = String(event.result); //decode the data to ActionScript using the JSON API //in this case, the JSON data is a serialize Array of Objects.var arr:Array = (JSON.decode(rawData) as Array); var dataArray:ArrayCollection = new ArrayCollection(arr); //Alert.show(dataArray.getItemAt(0).id);clientPagingBar2.dataGrid=DataGrid2;clientPagingBar2.orgData=dataArray;clientPagingBar2.dataBind();} ]]></fx:Script><mx:VBox width="100%" height="50%"><mx:Label text="客户端分页" /><mx:Canvas backgroundColor="white"><mx:VBox width="100%" height="50%" paddingBottom="10" paddingLeft="10" paddingRight="10" paddingTop="10" verticalScrollPolicy="off" horizontalScrollPolicy="off"><mx:DataGrid id="DataGrid1" verticalScrollPolicy="on" horizontalScrollPolicy="off"><mx:columns><mx:DataGridColumn headerText="订单ID" dataField="ID" /><mx:DataGridColumn headerText="订单编码" dataField="Code" /><mx:DataGridColumn headerText="金额" dataField="Total" /><mx:DataGridColumn headerText="客户" dataField="Customer" /><mx:DataGridColumn headerText="销售员" dataField="Register" /><mx:DataGridColumn headerText="备注说明" dataField="Memo" /><mx:DataGridColumn headerText="状态" dataField="State" /> </mx:columns></mx:DataGrid><control:PagingBar id="clientPagingBar1" /></mx:VBox></mx:Canvas><mx:Label text="服务器端分页" /><mx:Canvas backgroundColor="white"><mx:VBox width="100%" height="50%" paddingBottom="10" paddingLeft="10" paddingRight="10" paddingTop="10" verticalScrollPolicy="off" horizontalScrollPolicy="off"><mx:DataGrid id="DataGrid2" verticalScrollPolicy="on" horizontalScrollPolicy="off"><mx:columns><mx:DataGridColumn headerText="订单ID" dataField="id" /><mx:DataGridColumn headerText="订单编码" dataField="code" /><mx:DataGridColumn headerText="金额" dataField="total" /><mx:DataGridColumn headerText="客户" dataField="customer" /><mx:DataGridColumn headerText="销售员" dataField="register" /><mx:DataGridColumn headerText="备注说明" dataField="memo" /><mx:DataGridColumn headerText="状态" dataField="state" /> </mx:columns></mx:DataGrid><control:PagingBar id="clientPagingBar2" /></mx:VBox></mx:Canvas></mx:VBox></s:Application>?servlet处理类为
package com.test;import java.io.IOException;import java.io.PrintWriter;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.beans.MyObject;import net.sf.json.JSONArray;public class FindDataServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException { this.doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {System.out.println("执行Servlet了哦。。。。。。。。。。。。");List<MyObject> orgData=new ArrayList<MyObject>();for(int x= 1; x <= 555; x++ ){MyObject ob=new MyObject();ob.setId("CHENEY"+x); ob.setCode("HENAN"+x);ob.setTotal(x*10);ob.setCustomer("CUS"+x);ob.setRegister("EMP"+x); ob.setMemo("MEMO"+x);ob.setState("STATE"+x);orgData.add(ob);} JSONArray json=JSONArray.fromObject(orgData); String datas=json.toString(); System.out.println(datas); response.getWriter().write(datas);}}?当然这里JAVA程序也用到JSON相关类，一般要使用JSON的话要使用到六个包
?![Flex4之DataGrid示范【客户端和服务器端]](http://img.reader8.net/uploadfile/jiaocheng/20140197/2851/201401282151058233.png)
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RemoteObject 获取方式
?? mxml内容
<?xml version="1.0" encoding="utf-8"?><s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx" xmlns:control="com.control.*" creationComplete="creationCompleteHandle()" minWidth="955" minHeight="600" height="900"><fx:Style>Application{fontSize:12;}</fx:Style><fx:Declarations><s:RemoteObject id="findData" destination="findData" result="findDate_resultHandler(event)"/></fx:Declarations><fx:Script><![CDATA[import com.adobe.serialization.json.JSON;import mx.collections.ArrayCollection;import mx.controls.Alert;import mx.rpc.events.FaultEvent;import mx.rpc.events.ResultEvent;private var pageIndex:int=0;private var pageSize:int=5;private function creationCompleteHandle():void{var orgData:ArrayCollection = new ArrayCollection();for( var x:uint = 1; x <= 555; x++ ){var obj:Object = new Object();obj.ID = "id " + x.toString();obj.Code="order "+x;obj.Total=x*1000;obj.Customer= "customer "+x;obj.Register = "employee";obj.Memo="memo "+x; obj.State="auditing state"; orgData.addItem(obj);}clientPagingBar1.dataGrid=DataGrid1;clientPagingBar1.orgData=orgData;clientPagingBar1.dataBind();findData.findData();}protected function findDate_resultHandler(event:ResultEvent):void{var rawData:String = String(event.result); //decode the data to ActionScript using the JSON API //in this case, the JSON data is a serialize Array of Objects.var arr:Array = (JSON.decode(rawData) as Array); var dataArray:ArrayCollection = new ArrayCollection(arr); //Alert.show(dataArray.getItemAt(0).id);clientPagingBar2.dataGrid=DataGrid2;clientPagingBar2.orgData=dataArray;clientPagingBar2.dataBind();} ]]></fx:Script><mx:VBox><mx:Label text="客户端分页" /><mx:Canvas backgroundColor="white"><mx:VBox width="100%" height="100%" paddingBottom="10" paddingLeft="10" paddingRight="10" paddingTop="10" verticalScrollPolicy="off" horizontalScrollPolicy="off"><mx:DataGrid id="DataGrid1" verticalScrollPolicy="on" horizontalScrollPolicy="off"><mx:columns><mx:DataGridColumn headerText="订单ID" dataField="ID" /><mx:DataGridColumn headerText="订单编码" dataField="Code" /><mx:DataGridColumn headerText="金额" dataField="Total" /><mx:DataGridColumn headerText="客户" dataField="Customer" /><mx:DataGridColumn headerText="销售员" dataField="Register" /><mx:DataGridColumn headerText="备注说明" dataField="Memo" /><mx:DataGridColumn headerText="状态" dataField="State" /> </mx:columns></mx:DataGrid><control:PagingBar id="clientPagingBar1" /></mx:VBox></mx:Canvas><mx:Label text="服务器端分页" /><mx:Canvas backgroundColor="white"><mx:VBox width="100%" height="100%" paddingBottom="10" paddingLeft="10" paddingRight="10" paddingTop="10" verticalScrollPolicy="off" horizontalScrollPolicy="off"><mx:DataGrid id="DataGrid2" verticalScrollPolicy="on" horizontalScrollPolicy="off"><mx:columns><mx:DataGridColumn headerText="订单ID" dataField="id" /><mx:DataGridColumn headerText="订单编码" dataField="code" /><mx:DataGridColumn headerText="金额" dataField="total" /><mx:DataGridColumn headerText="客户" dataField="customer" /><mx:DataGridColumn headerText="销售员" dataField="register" /><mx:DataGridColumn headerText="备注说明" dataField="memo" /><mx:DataGridColumn headerText="状态" dataField="state" /> </mx:columns></mx:DataGrid><control:PagingBar id="clientPagingBar2" /></mx:VBox></mx:Canvas></mx:VBox></s:Application>?处理类
package com.test;import java.util.ArrayList;import java.util.List;import com.beans.MyObject;import net.sf.json.JSONArray;public class FindGridData {public String findData(){System.out.println("执行我了。。。。。。。。。。。。。。。");List<MyObject> orgData=new ArrayList<MyObject>();for(int x= 1; x <= 555; x++ ){MyObject ob=new MyObject();ob.setId("CHENEY"+x); ob.setCode("HENAN"+x);ob.setTotal(x*10);ob.setCustomer("CUS"+x);ob.setRegister("EMP"); ob.setMemo("MEMO"+x);ob.setState("STATE");orgData.add(ob);} JSONArray json=JSONArray.fromObject(orgData); String datas=json.toString(); System.out.println(datas); return datas;}}?JavaBean
MyObject.java
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package com.beans;public class MyObject {private String id ;private String code ;private int total ;private String customer ;private String register ;private String memo ;private String state ;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public int getTotal() {return total;}public void setTotal(int total) {this.total = total;}public String getCustomer() {return customer;}public void setCustomer(String customer) {this.customer = customer;}public String getRegister() {return register;}public void setRegister(String register) {this.register = register;}public String getMeno() {return memo;}public void setMemo(String memo) {this.memo = memo;}public String getState() {return state;}public void setState(String state) {this.state = state;}}?![Flex4之DataGrid示范【客户端和服务器端]](http://img.reader8.net/uploadfile/jiaocheng/20140197/2851/201401282151058234.png "点击查看原始大小图片")
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