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
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。
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
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
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;
}
}
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