Flex 自定义打印控件编写

打印历来是web应用一个比较棘手的问题，幸好flex web应用是运行在flash player上的，flash player可以访问打印机，所以flex 应用可以实现比较强大的打印功能。Flex 自身提供的printjob、flexprintjob相对来说用起来不是很方便，对于有严格纸张设置、翻页等打印需求，略显功能不足，因此需要基于printjob或flexprintjob来完善flex的打印功能，及自定义打印控件。

       本控件核心为：

       1）PrintManager，打印控制核心类

    2）IPrintableDocument，打印文档设置，打印文档有3部分组成，分别是：PrintableHeader、PrintableBody、PrintableFooter。

 

    因此，开发人员只要设计好printabledocument,重点排版好header、body、footer，然后调用PrintManager的打印即可打印printabledocument了。

<print:PrintableDocument         printableBody="{p_body}" printableFooter="{p_footer}" printableHeader="{p_header}">       <print:PrintableHeader width="100%" id="p_header" x="0" y="0" height="81" >        <mx:Label id="pageHeader" text="Sample Accounts" styleName="printTitle" width="100%" textAlign="center"/>        <mx:Label id="cityHeader" text="City Of Somewheretown" width="100%" textAlign="center" />        <mx:Label id="entityHeader" text="General Accounts" width="100%" textAlign="center"/>     </print:PrintableHeader>     <print:PrintableBody id="p_body" width="100%" bottom = "28" x="0" top="81">        <mx:PrintAdvancedDataGrid id="accountsDataGrid" designViewDataType="flat"                           dataProvider="{accounts}" horizontalGridLines="false" verticalGridLines="false"                           width="100%" height="100%" borderStyle="none" sortExpertMode="true" headerHeight="0"                           rowHeight="30">            <mx:columns>               <mx:AdvancedDataGridColumn headerText="Account Number" dataField="account" textAlign="center" width="100"/>               <mx:AdvancedDataGridColumn headerText="Control Account" dataField="control" textAlign="center" width="100"/>               <mx:AdvancedDataGridColumn headerText="Description" dataField="description" width="300"/>            </mx:columns>        </mx:PrintAdvancedDataGrid>     </print:PrintableBody>     <print:PrintableFooter id="p_footer" width="100%" height="28" bottom="0" left="0" printType="perpage">        <mx:Label text="Prepared by: Authorname" width="33%" textAlign="center"/>        <mx:Label text="Page {pageNumber} of {pageCount}" width="34%" textAlign="right"/>             <mx:Label id="pageFooter" text="Sample Accounts" width="33%"/>     </print:PrintableFooter> </print:PrintableDocument>

 

       附上控件核心类的相关代码。

       1、PrintManager

public class PrintManager     {        public function PrintManager()        {        }               public function print(document:IPrintableDocument, parent:UIComponent = null):Boolean        {            var printJob:PrintJob = new PrintJob();                       if (parent != null)              parent.addChild(document.displayObject());                        var printed:Boolean = printInternal(document, printJob);                                   if (parent != null)               parent.removeChild(document.displayObject());                         return printed;         }                 private functionunscaleDocument(document:IPrintableDocument):void         {             document.scaleX = 1.0;             document.scaleY = 1.0;             document.validateNow();         }                /**         * adjust print orientation         * scale the printdocument         */         private functionrotateDocumentForPaperOrientation(document:IPrintableDocument, printJob:PrintJob):void         {            document.x = 0;            document.y = 0;                       var scaleFactor:Number = 1.0;            //            document.scaleX = scaleFactor;            document.scaleY = scaleFactor;            document.validateNow();         }                private function printPage(document:IPrintableDocument, printJob:PrintJob):void        {            var width:Number = document.desiredWidth;            var height:Number = document.desiredHeight;            var page:Sprite = Sprite(document);            var printableArea:Rectangle = new Rectangle(0, 0, width, height);            printJob.addPage(page, printableArea);        }                public function printInternal(document:IPrintableDocument, printJob:PrintJob):Boolean         {            //start printer             if (!printJob.start()) {               return false;             }             document.moveToFirstPage();            unscaleDocument(document);            //adjust paper orientation            rotateDocumentForPaperOrientation(document, printJob);                       //add first print page          printPage(document, printJob);             while(document.validNextPage)            {               document.nextPage();               printPage(document, printJob);            }                        printJob.send();             return true;         }     }

       2、IPrintableDocument

public interface IPrintableDocument extends IUIComponent, IEventDispatcher     {        function nextPage():void;        function get validNextPage():Boolean;        function previousPage():void;        function moveToFirstPage():void;        function validateNow():void;        function displayObject():DisplayObject;        function get desiredWidth():Number;        function get desiredHeight():Number;        function get printableFooter():PrintableFooter;        function get printableHeader():PrintableHeader;        function get printableBody():PrintableBody;        function set printableBody(body:PrintableBody):void;        function set printableHeader(header:PrintableHeader):void;        function set printableFooter(footer:PrintableFooter):void;        function get totalPageCount():Number;        function get currentPageNumber():Number;     }

       3、PrintableDocument

public class PrintableDocument extends VGroup implementsIPrintableDocument     {        [Bindable]public var pageNumber:Number = 1;        [Bindable]public var pageCount:Number = 1;        private var _body:PrintableBody;        private var _header:PrintableHeader;        private var _footer:PrintableFooter;        private var _desiredWidth:Number = 595;        private var _desiredHeight:Number = 842;        //        public function PrintableDocument(){            this.gap = 0;        }               public function get desiredWidth():Number        {            return _desiredWidth;    //21cm, A4,1cm=28.346px        }               public function set desiredWidth(value:Number):void{            _desiredWidth = value;        }               public function set desiredHeight(value:Number):void{            _desiredHeight = value;        }               public function get desiredHeight():Number        {            return _desiredHeight;   //29.7cm, A4        }               public function get totalPageCount():Number{            return pageCount;        }               public function get currentPageNumber():Number{            return pageNumber;        }               public function displayObject():DisplayObject        {            return this;        }               public function get validNextPage():Boolean        {            return printableBody.printGrid.validNextPage;        }               public function nextPage():void        {            printableBody.printGrid.nextPage();            pageNumber++;                       if(pageNumber == 2)            {               removeHeaderFromLayout();            }            if(!validNextPage){               includeFooterInLayout();            }            validateNow();        }               /**         * move to previous page.         */        public function previousPage():void        {            printableBody.printGrid.previousPage();            pageNumber--;                       if (pageNumber == 1)            {               includeHeaderInLayout();            }            removeFooterFromLayout();            validateNow(); //         dispatchEvent(new Event("validPagesChanged"));        }               /**         * move to first page.         */        public function moveToFirstPage():void        {            pageNumber = 1;            printableBody.printGrid.moveToFirstPage();            includeHeaderInLayout();            removeFooterFromLayout();            validateNow();        }               /**         * calcutate page count.         */        public function calculatePageCount():void        {            var count:Number=1;            moveToFirstPage();            while(printableBody.printGrid.validNextPage)            {               count++;               if(count == 2)               {                   removeHeaderFromLayout();               }               printableBody.printGrid.nextPage();               validateNow();            }            pageCount = count;            moveToFirstPage();        }                      private function includeHeaderInLayout():void        {            printableHeader.includeInLayout = true;            printableHeader.visible = true;        }               private function removeHeaderFromLayout():void        {           if(printableHeader.printType==PrintableHeader.PRINTTYPE_FIRSTPAGE){               printableHeader.includeInLayout = false;               printableHeader.visible = false;            }        }               private function includeFooterInLayout():void{            printableFooter.includeInLayout = true;            printableFooter.visible = true;        }               private function removeFooterFromLayout():void{           if(printableFooter.printType==PrintableFooter.PRINTTYPE_LASTPAGE && validNextPage){               printableFooter.includeInLayout = false;               printableFooter.visible = false;            }        }                      public function get printableBody():PrintableBody{            return _body;        }               public function set printableBody(body:PrintableBody):void{            this._body = body;        }               public function get printableFooter():PrintableFooter{            return _footer;        }               public function setprintableFooter(footer:PrintableFooter):void{            this._footer = footer;        }               public function get printableHeader():PrintableHeader{            return this._header;        }               public function setprintableHeader(header:PrintableHeader):void{            this._header = header;        }     }

4、PrintableHeader、PrintableBody、PrintableFooter代码

<s:Group 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>     <s:Rect width="100%" height="100%">        <s:fill><s:SolidColor color="0xFF4500" /></s:fill>     </s:Rect>     <fx:Script>        <![CDATA[            /**             *[firstpage,perpage]<br/>             *firstpage,header区域只在第一页打印<br/>             *perpage,header区域每页都会打印             */            public var printType:String = "firstpage";            public static const PRINTTYPE_FIRSTPAGE:String ="firstpage";            public static const PRINTTYPE_PERPAGE:String = "perpage";        ]]>     </fx:Script> </s:Group>   Body： <s:Group 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="500">     <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.printing.PrintAdvancedDataGrid;            public var printGrid:PrintAdvancedDataGrid;        ]]>     </fx:Script> </s:Group>   Footer: <s:Group 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>     <s:Rect width="100%" height="100%">        <s:fill><s:SolidColor color="0xFF00ff" /></s:fill>     </s:Rect>     <fx:Script>        <![CDATA[            /**             *[lastpage,perpage]<br/>             *lastpage,footer区域只在最后一页打印<br/>             *perpage,footer区域每页都会打印             */            public var printType:String = "lastpage";            public static const PRINTTYPE_LASTPAGE:String = "lastpage";            public static const PRINTTYPE_PERPAGE:String = "perpage";        ]]>     </fx:Script> </s:Group>