Flex 4通过重写DataGridColumn和CheckBox类给DataGrid添加选择列-CheckBoxColumn

最近在尝试着用Flex做个文件按管理的工具，在文件列表中为了操作方便，想到了再列表控件DataGird中添加一个含有复选框的列，在表头的复选框可以实现全选功能，但DataGird自身并无此功能。参照网上的相关资料，总算折腾出来了，现把源码奉上，希望对需要的朋友有点帮助，不足之处也请高手指点。

最终的CheckBoxColumn包包含四个相关的类文件，分别是：

1、CenterCheckBox.as：通过重写CheckBox基类来实现复选框的居中显示；

2、CheckBoxColumn.as：继承自DataGridColumn的一个新类，为了实现需要，增添了几个新属性；

3、CheckBoxHeaderRenderer.as：继承自CenterCheckBox 类，用于DataGrid表头的复选框，实现全选功能；

4、CheckBoxItemRenderer.as：继承自CenterCheckBox 类，用于DataGrid表中的数据行；

各文件源码如下：
1、CenterCheckBox.as

 
  1. package Common.YotuoUpload.CheckBoxColumn 
  2. { 
  3.     import flash.display.DisplayObject;   
  4.     import mx.controls.CheckBox;   
  5.     import flash.text.TextField;   
  6.      
  7.     public class CenterCheckBox extends CheckBox   
  8.     {   
  9.         // 居中展现   
  10.         override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void   
  11.         {   
  12.             super.updateDisplayList(unscaledWidth, unscaledHeight);   
  13.             var n:int = numChildren;   
  14.             for(var i:int = 0; i < n; i++)   
  15.             {   
  16.                 var c:DisplayObject = getChildAt(i);   
  17.                 if( !(c is TextField))   
  18.                 {   
  19.                     c.x = Math.round((unscaledWidth - c.width) / 2);   
  20.                     c.y = Math.round((unscaledHeight - c.height) /2 );   
  21.                 }   
  22.             }   
  23.         }   
  24.     } 
  25. } 

2、DataGridColumn.as

 
  1. package Common.YotuoUpload.CheckBoxColumn 
  2. { 
  3.     import mx.controls.dataGridClasses.DataGridColumn; 
  4.      
  5.     public class CheckBoxColumn extends DataGridColumn{ 
  6.          
  7.         public var cloumnSelected:Boolean=false;//保存该列是否全选的属性（用户先点击全选后在手动的取消几行数据的选中状态时，这里的状态不会改变）           
  8.          
  9.         public var selectItems:Array = new Array();//用户保存用户选中的数据 
  10.          
  11.      
  12.         public function CheckBoxColumn(columnName:String=null){ 
  13.             super(columnName);  
  14.         } 
  15.     } 
  16. } 

3、CheckBoxHeaderRenderer.as

 
  1. package Common.YotuoUpload.CheckBoxColumn 
  2. { 
  3.     import flash.events.Event; 
  4.      
  5.     import mx.collections.ArrayCollection; 
  6.     import mx.controls.CheckBox; 
  7.     import mx.controls.DataGrid; 
  8.  
  9.     public class CheckBoxHeaderRenderer extends CenterCheckBox{    
  10.          
  11.         private var _data:CheckBoxColumn;//定义CheckBox列对象      
  12.         public function CheckBoxHeaderRenderer(){ 
  13.             super(); 
  14.             this.addEventListener(Event.CHANGE,onChange);//CheckBox状态变化时触发此事件 
  15.             this.toolTip = "全选"; 
  16.         } 
  17.          
  18.          
  19.         override public function get data():Object{ 
  20.             return _data;//返回的是CheckBox列的对象 
  21.              
  22.         } 
  23.          
  24.         override public function set data(value:Object):void{ 
  25.             _data = value as CheckBoxColumn; 
  26.             //trace(_data.cloumnSelected); 
  27.             selected = _data.cloumnSelected; 
  28.         } 
  29.          
  30.         private function onChange(event:Event):void{                 
  31.              
  32.             var dg:DataGrid = DataGrid(listData.owner);//获取DataGrid对象 
  33.             var column:CheckBoxColumn = dg.columns[listData.columnIndex];//获取整列的显示对象 
  34.              
  35.             var dgDataArr:ArrayCollection = dg.dataProvider as  ArrayCollection; 
  36.              
  37.             column.cloumnSelected = this.selected;//更改列的全选状态 
  38.              
  39.             column.selectItems = new Array();//重新初始化用于保存选中列的对象 
  40.              
  41.             if(this.selected){//如果为全部选中的化就将数据源赋值给column.selectItems，不是就不管他，上一步已经初始化为空 
  42.                 column.selectItems = (dg.dataProvider as ArrayCollection).toArray(); 
  43.                  
  44.             } 
  45.             if(dgDataArr.length>0){ 
  46.                 if(dgDataArr[0]!=""){ 
  47.                     for(var i:int = 0; i < dgDataArr.length ; i++){ 
  48.                         Object(dgDataArr[i]).dgSelected = this.selected;//更改没一行的选中状态 
  49.                     }  
  50.                 }   
  51.             }  
  52.             dgDataArr.refresh();//刷新数据源，达到强制更新页面显示效果的功能，防止在使用时没有在VO类中使用绑定而出现点击全选页面没有更改状态的错误       
  53.         } 
  54.     } 
  55. } 

4、CheckBoxItemRenderer.as

 
  1. package Common.YotuoUpload.CheckBoxColumn 
  2. { 
  3.     import flash.events.Event; 
  4.     import flash.events.MouseEvent; 
  5.     import mx.controls.CheckBox; 
  6.     import mx.controls.DataGrid; 
  7.      
  8.     public class CheckBoxItemRenderer extends CenterCheckBox{ 
  9.         private var currentData:Object; //保存当前一行值的对象 
  10.  
  11.         public function CheckBoxItemRenderer(){ 
  12.             super(); 
  13.             this.addEventListener(Event.CHANGE,onClickCheckBox); 
  14.             this.toolTip = "选择"; 
  15.         } 
  16.          
  17.         override public function set data(value:Object):void{ 
  18.             this.selected = value.dgSelected; 
  19.             this.currentData = value; //保存整行的引用 
  20.         } 
  21.          
  22.         //点击check box时，根据状况向selectedItems array中添加当前行的引用，或者从array中移除 
  23.         private function onClickCheckBox(e:Event):void{  
  24.             var dg:DataGrid = DataGrid(listData.owner);//获取DataGrid对象 
  25.             var column:CheckBoxColumn = dg.columns[listData.columnIndex];//获取整列的显示对象 
  26.             var selectItems:Array = column.selectItems; 
  27.             this.currentData.dgSelected = this.selected;//根据是否选中的状态，更改数据源中选中的标记 
  28.             if(this.selected){ 
  29.                 selectItems.push(this.currentData); 
  30.             }else{ 
  31.                 for(var i:int = 0; i<selectItems.length; i++){ 
  32.                     if(selectItems[i] == this.currentData){ 
  33.                         selectItems.splice(i,1) 
  34.                     } 
  35.                 } 
  36.             } 
  37.         } 
  38.     } 
  39. } 

调用示例：

1、在mxml中作为控件调用：

 
  1. <?xml version="1.0" encoding="utf-8"?>  
  2. <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"   
  3.                xmlns:s="library://ns.adobe.com/flex/spark"   
  4.                xmlns:mx="library://ns.adobe.com/flex/halo" minWidth="1024" minHeight="768" 
  5.                xmlns:CheckBoxColumn="Common.YotuoUpload.CheckBoxColumn.*" 
  6.                creationComplete="Init()">  
  7.     <fx:Script>  
  8.         <![CDATA[  
  9.             import Common.YotuoUpload.CheckBoxColumn.CheckBoxHeaderRenderer;  
  10.             import Common.YotuoUpload.CheckBoxColumn.CheckBoxItemRenderer;  
  11.             import mx.collections.ArrayCollection;  
  12.               
  13.             public var dataArray:ArrayCollection = new ArrayCollection;  
  14.               
  15.             private function Init():void{  
  16.                 dataArray.addItem({isSelected:false,name:'Christina Coenraets',phone:'555-219-2270',email:'ccoenraets@fictitious.com'});  
  17.                 dataArray.addItem({isSelected:false,name:'Joanne Wall',phone:'555-219-2012',email:'jwall@fictitious.com'});  
  18.                 dataArray.addItem({isSelected:false,name:'Maurice Smith',phone:'555-219-2012',email:'maurice@fictitious.com'});  
  19.                 dataArray.addItem({isSelected:false,name:'Mary Jones',phone:'555-219-2000',email:'mjones@fictitious.com'});  
  20.                 dataArray.addItem({isSelected:false,name:'God Win',phone:'555-219-2005',email:'godwin@fictitious.com'});  
  21.                 dgUser.dataProvider = dataArray;  
  22.             }  
  23.         ]]>  
  24.     </fx:Script>  
  25.     <mx:DataGrid id="dgUser" x="10" y="10" width="450" height="200">  
  26.         <mx:columns>  
  27.             <CheckBoxColumn:CheckBoxColumn dataField="isSelected" width="25"    
  28.                                            draggable="false" resizable="false" sortable="false" 
  29.                                            headerRenderer="{new ClassFactory(CheckBoxHeaderRenderer)}" 
  30.                                            itemRenderer="{new ClassFactory(CheckBoxItemRenderer)}" 
  31.                                            />  
  32.             <mx:DataGridColumn headerText="姓名" dataField="name"/>  
  33.             <mx:DataGridColumn headerText="电话" dataField="phone"/>  
  34.             <mx:DataGridColumn headerText="邮件" dataField="email"/>  
  35.         </mx:columns>  
  36.     </mx:DataGrid>  
  37. </s:Application> 

2、通过代码动态调用：

 
  1. <?xml version="1.0" encoding="utf-8"?>  
  2. <s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"   
  3.                xmlns:s="library://ns.adobe.com/flex/spark"   
  4.                xmlns:mx="library://ns.adobe.com/flex/halo" minWidth="1024" minHeight="768" 
  5.                creationComplete="Init()">  
  6.     <fx:Script>  
  7.         <![CDATA[  
  8.             import mx.controls.dataGridClasses.DataGridColumn;  
  9.             import Common.YotuoUpload.CheckBoxColumn.CheckBoxColumn;  
  10.             import Common.YotuoUpload.CheckBoxColumn.CheckBoxHeaderRenderer;  
  11.             import Common.YotuoUpload.CheckBoxColumn.CheckBoxItemRenderer;  
  12.             import mx.collections.ArrayCollection;  
  13.               
  14.             public var dataArray:ArrayCollection = new ArrayCollection;  
  15.               
  16.             private function Init():void{  
  17.                 dataArray.addItem({isSelected:false,name:'Christina Coenraets',phone:'555-219-2270',email:'ccoenraets@fictitious.com'});  
  18.                 dataArray.addItem({isSelected:false,name:'Joanne Wall',phone:'555-219-2012',email:'jwall@fictitious.com'});  
  19.                 dataArray.addItem({isSelected:false,name:'Maurice Smith',phone:'555-219-2012',email:'maurice@fictitious.com'});  
  20.                 dataArray.addItem({isSelected:false,name:'Mary Jones',phone:'555-219-2000',email:'mjones@fictitious.com'});  
  21.                 dataArray.addItem({isSelected:false,name:'God Win',phone:'555-219-2005',email:'godwin@fictitious.com'});  
  22.                   
  23.                 var _checkBoxCloumn:CheckBoxColumn = new CheckBoxColumn();  
  24.                 _checkBoxCloumn.dataField = "isSelected";  
  25.                 _checkBoxCloumn.headerRenderer = new ClassFactory(CheckBoxHeaderRenderer);  
  26.                 _checkBoxCloumn.itemRenderer = new ClassFactory(CheckBoxItemRenderer);  
  27.                 _checkBoxCloumn.width = 30;  
  28.                 _checkBoxCloumn.sortable = false;  
  29.                 _checkBoxCloumn.draggable = false;  
  30.                   
  31.                 var _nameColumn:DataGridColumn = new DataGridColumn();  
  32.                 _nameColumn.headerText = "姓名";  
  33.                 _nameColumn.dataField = "name";  
  34.                   
  35.                 var _telColumn:DataGridColumn = new DataGridColumn();  
  36.                 _telColumn.headerText = "电话";  
  37.                 _telColumn.dataField = "phone";  
  38.                   
  39.                 var _emailColumn:DataGridColumn = new DataGridColumn();  
  40.                 _emailColumn.headerText = "邮件";  
  41.                 _emailColumn.dataField = "email";  
  42.                   
  43.                 dgUser.columns = new Array(_checkBoxCloumn,_nameColumn,_telColumn,_emailColumn);  
  44.                 dgUser.dataProvider = dataArray;  
  45.             }  
  46.         ]]>  
  47.     </fx:Script>  
  48.     <mx:DataGrid id="dgUser" x="10" y="10" width="450" height="200" />  
  49. </s:Application> 

PS：该组件要求在数据源中存在属性isSelected（Boolean类型，用来记录当前行是否被选中）属性，这样就限制了程序的通用性，试了很多方法都未很好解决，希望有办法解决的朋友给以指点。

示例运行效果：

 image

本文作者：宜城小子  发于：http://blog.yotuo.net（转载请保留此信息）
原文链接：http://blog.yotuo.net/post/2009/11/DataGrid-CheckBoxColumn.html

 

posted @ 2009-11-04 09:11  宜城小子  阅读(10109)  评论(2)  编辑  收藏  举报