Flex 打印常使用PrintDataGrid，但会有一些问题，不支持表格单元格合并，有的可能需要打印一些flex组件和容器（VBox, HBox, Text, Image）等。重写flex的Grid表格，Grid类似HTML的table, 能很好支持单元格合并，单元格中加入组件和容器。

自定义PrintDataGrid：

public class PrintDataGrid extends Grid

    {

       public static const pageHeight:int = 1023;

 

       private var _realWidth:int;

 

       public function PrintDataGrid()

       {

           this.horizontalScrollPolicy = ScrollPolicy.OFF;

           this.verticalScrollPolicy = ScrollPolicy.OFF;

 

           super();

       }

 

       public function addGridRow(gridRow:RowGrid):void {

           addCells(gridRow.getAvailableCell(), gridRow.height);

       }

 

       private function addCells(cells:Array, height:Number):void {

           var gridRow:GridRow = new GridRow();

           for each(var cell:GridCell in cells) {

              gridRow.addChild(cell);

           }

           gridRow.height = height;

           this.addChild(gridRow);

       }

 

       public function get realWidth():int

       {

           return _realWidth;

       }

 

       public function set realWidth(value:int):void

       {

           _realWidth = value;

       }

    }

 

Adobe对于多页打印或打印预览都没有提供一个很好的解决办法，但可以根据Grid中GridRow的height,计算自动拆分表格，将一个大的Grid拆分每一个页面一个Grid，进行分页预览和打印。大概的算法：根据每页的height值计算一个页面能存放多少Grid的GridRow，超过的拆分到下一个页面，如果需要拆分的单元格存在被合并的情况，也就是GridItem 中RowSpan > 1, 则需要将一个GridItem，分为两个GridItem，而这两个的GridItem的rowSpan之和为原来的GridItem的RowSpan。

 合并单元格拆分：

public function splitRowSpan(gridCellArray:GridCellArray):void {

           if(cells.length == 0) {

               return;

           }

           for(var i:int = 0; i < cells.length; i++) {

              var gridCell:GridCell = cells[i] as GridCell;

              if(gridCell == null) {

                  continue;

              }

              var splitCell:GridCell = null;

              if (gridCell.isRemove) {

                  splitCell = gridCell.mergerCell;

              }

              if (splitCell == null) {

                  continue;

              }

              if (gridCell.rNum == splitCell.rNum) {

                  continue;

              }

              var orgRowSpan:int = splitCell.rowSpan;

              var extRowSpan:int = gridCell.rNum - splitCell.rNum;

             

              var content:DisplayObject = splitCell.getChildAt(0);

             

              var topCellHeight:Number = getExtRowSpanHeight(splitCell.rNum, splitCell.rNum + extRowSpan, gridCellArray);

              var bottomCellHeight:Number = getExtRowSpanHeight(splitCell.rNum + extRowSpan, splitCell.rNum + splitCell.rowSpan, gridCellArray);

             

              splitCell.rowSpan = extRowSpan;

              splitCell.height = topCellHeight;

              if(topCellHeight < bottomCellHeight) {

                  splitCell.removeAllChildren();

              }

             

              var  bottomCell:GridCell = splitCell.newGridCell();

              bottomCell.rowSpan = orgRowSpan - extRowSpan;

              bottomCell.colSpan = splitCell.colSpan;

              bottomCell.height = bottomCellHeight;

              bottomCell.rNum = gridCell.rNum;

              bottomCell.cNum = gridCell.cNum;

              if(topCellHeight < bottomCellHeight) {

                  bottomCell.addChild(content);

              }

             

              var gridRow:RowGrid = gridCellArray.getRowGrid(gridCell.rNum);

              gridRow.setCell(bottomCell, bottomCell.cNum);

              if (bottomCell.rowSpan > 1 || bottomCell.colSpan > 1) {

                  gridCellArray.mergerGridCell(bottomCell);

              }

           }

       }