flex分页控件的使用

fhuan123

分页显示数据是网站浏览中必备的元素之一，在FLEX中通过数据分页的方法来获取当前显示数据，即能降低网络传的负担同时也能减少Flex的处理工作。
分页控件需要的功能有：首页，上一页，下一页，未页和页数跳转等。
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定义分页控件的事件：PageChange

相关事件参数对象：
package { import flash.events.Event; import mx.events.IndexChangedEvent; public class PageChangeEvent extends flash.events.Event { public function PageChangeEvent(pageindex:int,pagesize:int) { super("PageChange"); PageIndex= pageindex; PageSize =pagesize; } public var PageIndex:int=0; public var PageSize:int=0; public function Filter(list:Array):Array { var newlist:Array = new Array(); var start:int = PageSize*PageIndex; var end:int = start+PageSize; for(var i:int = start;i<end;i++) { if(i< list.length) { newlist.push(list); } else break; } return newlist; } } }
分页控件的代码：
<?xml version="1.0" encoding="utf-8"?> <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" width="466" height="40"> <mx:Metadata> [Event(name="PageChange", type="PageChangeEvent",bubbles="true",cancelable="true")] </mx:Metadata> <mx:Button click="method_le()" id="c_le" enabled="false" x="10" y="10" fontFamily="" width="24" height="24" minWidth="24" minHeight="24"> <mx:icon>@Embed('LE.gif')</mx:icon> </mx:Button> <mx:Button click="method_l()" id="c_l" enabled="false" x="42" y="10" fontFamily="" width="24" height="24" minWidth="24" minHeight="24"> <mx:icon>@Embed('L.gif')</mx:icon> </mx:Button> <mx:ComboBox rowCount="10" change="method_select()" id="c_select" enabled="false" x="74" y="10" width="54"></mx:ComboBox> <mx:Button click="method_r()" id="c_r" enabled="false" x="136" y="10" fontFamily="" width="24" height="24" minWidth="24" minHeight="24"> <mx:icon>@Embed('R.gif')</mx:icon> </mx:Button> <mx:Button click="method_re()" id="c_re" enabled="false" x="168" y="10" fontFamily="" width="24" height="24" minWidth="24" minHeight="24"> <mx:icon>@Embed('RE.gif')</mx:icon> </mx:Button> <mx:Script> <![CDATA[ import mx.controls.Alert; private var mRecordCount:int=0; private var mPageSize:int =20; private var mPageIndex:int =0; private var mPageCount:int = 0; public function method_l():void { mPageIndex=mPageIndex-1; SetState(); OnPageChange(); } public function method_le():void { mPageIndex =0; SetState(); OnPageChange(); } public function method_r():void { mPageIndex=mPageIndex+1; SetState(); OnPageChange(); } public function method_re():void { mPageIndex=mPageCount-1; SetState(); OnPageChange(); } public function method_select():void { mPageIndex = c_select.selectedItem.data; SetState(); OnPageChange(); } public function get PageIndex():int { return mPageIndex; } //设置记录总数 public function set RecordCount(count:int):void { mRecordCount= count; if(count >0) { SetState(); } } private function SetState():void { if(mRecordCount%mPageSize > 0) { mPageCount = mRecordCount/mPageSize+1; } else { mPageCount = mRecordCount/mPageSize; } var pages:Array = new Array(); for(var i:int =1;i<=mPageCount;i++) { pages.push( {label:i.toString(), data:i-1}); } c_select.dataProvider= pages; c_select.selectedIndex= mPageIndex; if(mPageCount>1) { c_select.enabled=true; c_l.enabled=true; c_le.enabled=true; c_r.enabled=true; c_re.enabled=true; if(mPageIndex==0) { c_l.enabled=false; c_le.enabled=false; } if(mPageIndex == mPageCount-1) { c_r.enabled=false; c_re.enabled=false; } } else { c_select.enabled=false; c_l.enabled=false; c_le.enabled=false; c_r.enabled=false; c_re.enabled=false; } pageinfo.text="Records:" + mRecordCount+"/" + mPageCount+"pages"; } //获取记录总数 public function get RecordCount():int { return mRecordCount; } //打开分页控件 public function Open():void{ mPageIndex =0; OnPageChange(); } //刷新当前页面 public function Refresh():void { OnPageChange(); } private function OnPageChange():void { var e:PageChangeEvent = new PageChangeEvent(mPageIndex, mPageSize); dispatchEvent(e); } ]]> </mx:Script> <mx:Label x="200" y="10" width="175" fontSize="12" id="pageinfo"/> </mx:Canvas> 用例页面代码： <?xml version="1.0" encoding="utf-8"?> <mx:Application initialize="oninit()" xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" xmlns:ns1="Units.*" xmlns:ns2="*"> <mx:Script> <![CDATA[ import mx.controls.Alert; import flash.events.Event; import Units.*; private var datas:Array = new Array(); function oninit():void { for(var i:int=0;i<1110;i++) { datas.push({UserName:"Henry"+i,Notes:" GuangZhou " +i}) } pagebar1.RecordCount =datas.length; pagebar1.Open(); } function pagechange(e:PageChangeEvent):void { datalist.dataProvider = e.Filter(datas) } ]]> </mx:Script> <mx:DataGrid width="100%" id="datalist"> <mx:columns> <mx:DataGridColumn headerText="UserName" dataField="UserName"/> <mx:DataGridColumn headerText="Notes" dataField="Notes"/> </mx:columns> </mx:DataGrid> <ns2:PageBar id="pagebar1" PageChange="pagechange(event)"> </ns2:PageBar> </mx:Application>